Recently in Astronomy and cosmology Category

BBC: Yesterday an international team of astronomers and engineers succeeded in linking all four of the large telescopes that make up the European Southern Observatory's Very Large Telescope, located on Cerro Paranal in Chile's Atacama Desert. Each of the four has been up and running since at least 2000. However, when linked together via interferometry, they form the biggest ground-based optical telescope on Earth, which offers very high spatial resolution and zooming capabilities. "From now on we'll be able to observe things we were not able to observe before," said Frederic Gonte, head of instrumentation.

Telegraph: Researchers at Imperial College London have determined that life could not exist on the surface of Mars because of a super drought that lasted hundreds of millions of years, writes Nick Collins for the Telegraph. Experts spent three years studying individual soil particles collected in 2008 by NASA's Phoenix spacecraft. Despite a warmer and wetter period in Mars's distant past, the 5000 years or so that it lasted was simply too brief for life to have established itself on the surface. "Future NASA and ESA [European Space Agency] missions that are planned for Mars will have to dig deeper to search for evidence of life, which may still be taking refuge underground," said Tom Pike, lead author of a paper published in Geophysical Research Letters.

Science: A new analysis of observations made over the last 160 years suggests that Polaris, also called the North Star, is losing nearly the equivalent of Earth's mass, or just under one millionth of its own mass, every year. Hilding Neilson of the University of Bonn in Germany and colleagues studied the variation in Polaris's pulse—the approximately four-day cycle over which the star grows dimmer and brighter—and found that it's slowing by about 4.5 seconds every year. In 1844, however, it was about 12 minutes slower than it is now. If Polaris is an older star that's burning helium nuclei in its core, then its pulse is decreasing at a faster rate than it should, according to the standard model of stellar evolution. Loss of mass is the only thing that can account for the discrepancy, according to Neilson.

Telegraph: Two British amateur astronomers, Chris Holmes and Lee Threapleton, may have discovered a new planet. Inspired by Brian Cox’s Stargazing Live TV series, they studied time-lapse images of stars posted online at Planethunters.org. The site, which is part of the Zooniverse citizen science project, encourages users to identify extrasolar planets from data recorded by the Kepler space telescope. Holmes and Threapleton looked for anomalies in light patterns and found that a planet appeared to be orbiting a sun called SPH10066540, which lies 600–3000 light-years away. Thought to be gaseous and about the size of Neptune, the new planet will be named Threapleton Holmes B, provided the discovery is authenticated.

BBC: The Stratospheric Observatory for Infrared Astronomy, or SOFIA, is a 15-ton telescope mounted in the back of a converted Boeing 747. The telescope can see in both the visible and IR spectra. The first of SOFIA's images of the Orion nebula were released in late December, and James De Buizer of the Universities Space Research Association and colleagues examined the data, focusing on the region around the Becklin-Neugebauer object, one of the brightest IR objects in the sky. The object itself was thought to be the main source of the nebula's IR emission, but the new images show that something else they were previously unaware of—perhaps a small protocluster of stars—is shining very brightly in the IR there. SOFIA is a user facility; scientists can propose experiments and get time in the air to pursue them. A new call is out for the next year of missions.

Science: Representing five years of work in imaging 10 million galaxies at distances of about 6 billion light-years, the new dark-matter map is 100 times larger than the largest one to date, writes Govert Schilling for Science. Although dark matter, which represents 98% of the mass of the universe, cannot be seen directly, it exerts a gravitational pull on normal matter, including light. By measuring that pull on starlight, astronomers were able to map its distribution. The new map shows that dark matter is concentrated in huge clumps and filaments, with large empty regions in between. Astrophysicist Ludovic Van Waerbeke of the University of British Columbia in Vancouver, Canada, and colleagues presented their results at the 219th meeting of the American Astronomical Society. Scientists hope that by plotting the distribution of dark matter throughout space, they will come closer to understanding what it is.

Science: Last week NSF announced that it does not expect to fund the building of either the Thirty Meter Telescope (TMT) or the Giant Magellan Telescope (GMT) until 2020 at the earliest. The two university consortia in charge of the giant ground-based telescope projects have raised tens of millions of dollars in the hope that NSF would be able to come up with the balance, and both the TMT and the GMT were scheduled to start operations before 2020. The hope was not unfounded. In its most recent decadal survey, the National Academy of Sciences recommended that NSF should pick and fund one project, a recommendation that Congress later mandated but didn't explicitly fund. To stay on schedule, both teams will need to raise hundreds of millions of dollars in private funding or else find international partners.

BBC: Two new neutrino-hunting telescopes are being designed for underwater locations, writes Katia Moskvitch for the BBC. To screen out other particles that bombard Earth from above, such telescopes need to be in as deep and dark a place as possible, such as inside mountains, underground, and even in solid ice. The Baikal-GVD (Gigaton Volume Detector) will replace the existing NT-200, a small octopus-like device floating more than 1 km below the surface of Russia’s Lake Baikal, the world’s deepest lake. Much more massive will be the KM3NeT (kilometer-cubed neutrino telescope), which will sit at depths of 3–5 km at the bottom of the Mediterranean Sea. The telescope will consist of hundreds of vertical strings, each supporting dozens of sensors. Because each string is almost 1 km long, the entire structure will be taller than the tallest building in the world, the 830-m Burj Khalifa in Dubai. To cover the entire Earth, those two big, powerful detectors, both located in the Northern Hemisphere, will complement IceCube, located in the ice at the South Pole. Scientists believe that neutrinos, which can speed through space with an almost total lack of deviation or absorption, could hold the key to understanding the early universe.

Talking Points Memo: The Mars rover Curiosity, which launched 26 November aboard NASA’s Mars Science Laboratory, has switched on one of its instruments in flight. During Curiosity’s eight-month trip, its radiation assessment detector (RAD) will monitor high-energy atomic and subatomic particles from the Sun, distant supernovas, and other sources. The rover also will monitor radiation on the surface of Mars after its August 2012 landing. One of 10 precision instruments on board, “RAD is serving as a proxy for an astronaut inside a spacecraft on the way to Mars,” according to a NASA news release from RAD’s principal investigator Don Hassler, from the Southwest Research Institute in Boulder, Colorado. “The instrument is deep inside the spacecraft, the way an astronaut would be. Understanding the effects of the spacecraft on the radiation field will be valuable in designing craft for astronauts to travel to Mars.”

Science: A new object has been spotted near Sagittarius A*, the black hole at the center of the Milky Way, and it may be on its way to being devoured. Stefan Gillessen and Reinhard Genzel of the Max Planck Institute for Extraterrestrial Physics in Garching, Germany, and their colleagues observed the center of our galaxy at IR wavelengths using the European Southern Observatory's Very Large Telescope in Chile. The instrument picked up a small gas cloud that appeared to be getting closer and closer to Sagittarius A* over a period of nine years. Because the astronomers detected the object at a wavelength of 3.76 microns but not at 2.16 microns, they believe it's a cloud of gas, rather than a star, which would be brighter at the shorter wavelength. The object has doubled its speed from 1200 km/s in 2004 to 2350 km/s in 2011. Already beginning to stretch like interstellar spaghetti, the cloud will be close enough to the black hole in 2013 to be torn apart, fall in, and produce x rays observable from Earth. Andrea Ghez of UCLA has a different interpretation of the data: It's evidence of a star surrounded by dust that has absorbed visible light and is re-emitting it at IR wavelengths. If that's the case, the object won't fall into the black hole in 2013, but will shoot past it.

Science: Cool giant stars spin slowly on their surfaces, but what about their cores? Paul Beck of the Catholic University of Leuven in Belgium and colleagues have reported that the cores of three yellow giant stars, each 20% to 50% more massive than our Sun, spin at least ten times faster than their surfaces. Beck's team studied data from NASA's Kepler spacecraft, which monitors the variations in starlight that occur when planets pass in front of their star. Oscillations within a star—called asteroseismological vibrations—can also cause starlight to vary, and they provide information about stars' internal structure. The discovery implies that our Sun's core will also spin faster than its surface when it becomes a giant; this may affect how it sheds its outer atmosphere and transforms from a red giant into a white dwarf.

Washington Post: The search for Earth-like planets circling other stars is escalating, with NASA’s $600 million Kepler mission having found 2326 candidate planets, of which 207 are similar in size to Earth. Ten of those, which includes the latest find—Kepler-22b—orbit their stars in the so-called habitable zone, a balmy band of space where water can be liquid. With a surface temperature of about 22 °C, Kepler-22b, located some 600 light-years from Earth, looks to be the best candidate so far. It orbits a star very similar to our own Sun and its year is almost the same length as Earth’s, said Natalie Batahla, a Kepler scientist. Whether Kepler-22b has a surface and an atmosphere is yet to be determined, however; more observations need to be made with other, ground-based telescopes. According to Batahla, “We are getting really close; we are really homing in on the true Earth-sized habitable planets.”

Nature: Astronomers have discovered the two most massive black holes known in the universe to date, writes Ron Cowen for Nature. Using instruments on the Keck II and Gemini North telescopes on Hawaii’s Mauna Kea, Chung-Pei Ma (University of California, Berkeley) and colleagues found that a cluster galaxy called NGC 3842 houses a black hole with a mass equivalent to 9.7 billion Suns and that another galaxy, NGC 4889, has a black hole with an estimated mass of at least 20 billion Suns. The previous record holder has a mass of 6.7 billion Suns. The galaxies are about 300 million light-years from Earth—relatively close by cosmic standards. Because supermassive black holes formed early in the universe, the team’s findings, published this week in Nature, suggest that the two newly discovered black holes could represent a missing link to the brightest quasars from early cosmic times. Also, because of their unusually large mass, they may have evolved differently from smaller black holes.

National Geographic: The two Voyager spacecraft, first launched more than 30 years ago, have detected a type of UV radiation coming from the Milky Way that until now was rendered effectively invisible by the Sun's radiation. Known as Lyman-alpha, the radiation arises when hydrogen's lone electron hops down from the n = 2 quantum level to the n = 1 level. Regions rich in Lyman-alpha emission have been observed in other galaxies and associated with their stellar nurseries. Most of the emission that the Voyager probes have detected in our own galaxy also appears to emanate from star-forming regions. The new data may ultimately aid in the detection of the first appearance of stars in the universe.

Space.com: Scientists have been puzzled by the discovery of a number of ancient stars that contain unusually high levels of heavy elements such as gold, platinum, and uranium, because the heaviest elements are usually found at those levels only in much later generations of stars. Helium, hydrogen, and lithium were the first elements to form in the early universe. Heavier elements, up to iron in the periodic table, formed later inside stars. And the heaviest elements formed in supernovae. After a few hundred million years, all the known chemical elements existed, but the oldest stars that are still around today should contain only a fraction of the amount of heavy elements seen in the Sun and younger stars. Using data from the Nordic Optical Telescope (NOT), astronomers from the Niels Bohr Institute in Copenhagen and Michigan State University have found evidence to support one of two theories that seek to explain the anomaly. In one theory, the anomalous enrichment came from the stars' binary companions. In the other theory, which is more consistent with the NOT data, the enrichment comes from a previous generation of stars that seeded the local interstellar medium. “What this tells is how new elements and new stars formed in infant galaxies and why the sun, planets and we ended up having the chemical composition we do,” said Terese Hansen, lead author on a paper published in Astrophysical Journal Letters.

Space.com: Researchers studying the black hole Cygnus X-1, which is part of a binary-star system, have reported the most detailed look yet at one of the strongest x-ray sources seen from Earth. Using data collected by the Very Large Baseline Array and other instruments, the team has calculated the distance to Cygnus X-1, the mass of the black hole, and its extreme spin. Fifteen times as massive as the Sun, the black hole spins quickly yet progresses slowly through the galaxy. From such information, the team is beginning to piece together information about the black hole’s state today and draw conclusions about its origins, writes Nola Taylor Redd for Space.com.

Wired: Using a sub millimeter wavelength camera on the Atacana Pathfinder Experiment (APEX) telescope, a team led by Thomas Preisbisch, of Ludwig-Maximilians University in Germany, have captured images of star formation in the Carina Nebula. The nebula contains dense clouds of gas and dust that form very large, bright, short-lived stars that detonate as supernovas within a few million years. The gas near the blasts gets pushed into denser masses, which causes more stars to form.

Discovery News: An ongoing study of gas in distant galaxies by Jason Prochaska of the University of California's Lick Observatory and his colleagues has led to the discovery of two clouds made solely of hydrogen and its variant, deuterium, about 12 billion light-years away in the constellations of Ursa Major and Leo. According to the current cosmological model, the three lightest elements (hydrogen, helium, and lithium) formed right after the Big Bang about 13.7 billion years ago, and all other elements formed inside stars much later. The discovery could give insight into how galaxies get the gas they need to form stars, and it also supports the prevailing cosmological model ΛCDM.

Space.com: Despite a successful launch yesterday, Russia’s Phobos-Grunt spacecraft is stuck in Earth orbit after its thrusters failed to fire and send it on toward Mars. Engineers now have about three days to figure out what went wrong and fix the problem. After that time, Phobos-Grunt’s batteries will run out and the spacecraft will become just another piece of space debris orbiting Earth. China also has a stake in the venture because its first Mars probe, Yinghuo 1, is attached to Phobos-Grunt. This is Russia's third attempt to send a probe to the Martian moons; the other two missions, launched by the USSR in the 1980s, ended in failure.

Nature: After some 15 years, Russia is attempting to reignite its space program with the 8 November launch of its Phobos-Grunt spacecraft. The mission is two-pronged: to carry out scientific measurements on the surface of Phobos, the larger of Mars's two moons, and to bring back to Earth a few hundred grams of pebbles and dust collected from the moon’s surface. From the soil sample, scientists hope they will also find particles of material from Mars that they think could have been ejected from the planet’s surface by asteroid bombardment some 4 billion years ago. They also hope to use the material to determine Phobos’s age and origin and to see whether it contains any organic matter. "The major outcome is that Russia might establish its credibility again," said Roald Sagdeev, a former director of the Space Research Institute in Moscow who is now at the University of Maryland in College Park.

BBC: Astronomers using the Fermi Gamma-ray Space Telescope have spotted the youngest and brightest millisecond pulsar ever. Located about 27 000 light-years away in the Sagittarius constellation, the pulsar lies within a globular cluster, a dense spherical field of hundreds of thousands of old stars held together by gravity, writes Jason Palmer for the BBC. Because of the amount of light given off by the cluster, the single pulsar had to be very bright to be seen, which is unusual as pulsars tend to be very weak. This one was shining in the highest-energy light we know of: gamma rays. The researchers predict a short lifetime for J1823−3021A, however, as it is spinning down quickly—meaning the pauses between its beam pulses are growing longer and longer. Because this is the first gamma-ray pulsar that scientists have seen, it's not yet known whether they are rare or whether their detection simply awaited the right equipment—gamma-ray telescopes. The Fermi collaboration published its results online yesterday in Science.

MSNBC: Researchers have proposed a novel way of detecting extraterrestrial life: looking for artificial illumination. They hypothesize that if humans light up their cities at night, perhaps other beings do as well. In a paper submitted to the journal Astrobiology, Abraham Loeb of Harvard University and Edwin Turner of Princeton University suggest looking at the change in light from an exoplanet as it moves around its star; if the orbit is elliptical, the amount of reflected light will change with the distance from its star, but the amount of artificial light should remain constant. Unfortunately, at present, Earth’s day side is some 600 000 times brighter than its night side. For the method to work, any artificial brightness of the night side would have to be comparable to the natural brightness of the day side. Nevertheless, as radio-based searches have yet to turn up any sign of intelligent life on other worlds, and as new and better telescopes are being deployed, searching for brightly lit alien cities may one day prove viable.

Baltimore City Paper: Yesterday the US Senate approved full funding of the James Webb Space Telescope through its 2018 launch. As reported earlier, the JWST project, the successor to the Hubble Space Telescope, has been plagued with cost overruns and delays. Although the Republican-dominated House of Representatives had proposed cutting its funding, Senator Barbara Mikulski (D-MD) has proven its biggest advocate and pushed hard to keep it in the Senate's version of the budget. “The Webb Telescope supports 1200 jobs and will lead to the kind of innovation and discovery that have made America great,” she said. “It will inspire America’s next generation of scientists and innovators that will have the new ideas that lead to new products and new jobs.” The next hurdle will be keeping JWST funding alive as part of reconciling the Senate and House versions of the 2012 budget.

Guardian: With the successful launch of its prototype space-delivery vehicle, Shenzhou 8, China has taken another step toward building its own space station. Within the next two days, Shenzhou 8 should dock with the Tiangong 1 module, which was launched about a month ago. The docking involves some difficult maneuvers that will prove a further test of China’s space readiness. "Mastering the technology of rendezvous and docking will lay a firm foundation for China to build a space station," said Zhou Jianping, the chief designer of China's manned space engineering project.

Astronomy: A new study has found that dark matter in dwarf galaxies is distributed smoothly rather than being densely clumped at their centers as the standard cosmological model had predicted. Dwarf galaxies are believed to be about 99% dark matter. Matt Walker from the Harvard–Smithsonian Center for Astrophysics and Jorge Penarrubia from the University of Cambridge determined the positions and velocities of thousands of stars in two Milky Way neighbors, the Fornax and Sculptor dwarf galaxies. From their measurements, the researchers inferred the dwarf galaxies' dark matter distributions and concluded that either normal matter affects dark matter more than scientists thought, or dark matter isn’t as cold and slow-moving as previously predicted. Their findings will be published in an upcoming issue of the Astrophysical Journal.

Ars Technica: Blue stragglers are stars that burn brighter, hotter, and bluer—and therefore look much younger—than neighboring stars that formed at the same time. It's been theorized that they incorporated extra hydrogen, which helped them burn more intensely, but it wasn't known whether they merged with other stars, collided with them, or stole hydrogen from companion stars. Aaron Geller of Northwestern University and colleagues used the WIYN Observatory in Tucson, Arizona, to analyze 21 blue stragglers in the cluster NGC 188, in the constellation Cepheus, and found that 16 of them have a companion star with about half the mass of our Sun. Theoretical models indicate that the mass transfer necessary for a giant main sequence star to feed its hydrogen and helium to a blue straggler would leave behind a carbon-oxygen-rich white dwarf of about that mass. Geller and his team are going to use the Hubble Space Telescope to confirm whether mass transfer is still taking place between the dwarf remnants and the stragglers they orbit.

ABC News: Astronomers using the W. M. Keck Observatory's telescopes on Hawaii’s Mauna Kea have taken the first direct image of a planet being formed, writes Audrey McAvoy for the Associated Press. Until now young planets had been difficult to detect because the stars they orbit are so bright. Adam Kraus of the University of Hawaii and Michael Ireland of Australia’s Macquarie University overcame that obstacle by altering the shape of the telescope’s mirror and masking most of its surface. According to Kraus and Ireland, the planet is being formed from dust and gas circling a 2-million-year-old star, about 450 light-years from Earth. Their observations should help further the study of planetary science by determining when and where planets form in relation to the stars they orbit.

Los Angeles Times: Private commercial launch providers, such as Space Exploration Technologies Corp (SpaceX), may soon be able to compete with United Launch Alliance (ULA)—a joint venture between Lockheed Martin and Boeing—for launching national-security-related satellites into outer space. An agreement has been signed by several government agencies to establish the criteria, including detailed technical requirements and a successful launch record, for launching government payloads. On a related note, ULA is pushing for a five-year block buy of 40 of its rocket booster cores. The Government Accountability Office has raised several serious questions concerning the proposal, among them the possibility that such a block purchase could kill opportunities for competition by forcing the government to commit to more boosters than are actually needed.

Nature: The US National Solar Observatory (NSO) is working with an officially appointed arbiter to resolve challenges to building the Advanced Technology Solar Telescope (ATST) on the summit of Haleakala, the highest mountain on the Hawaiian island of Maui. The ATST would have twice the aperture of existing solar telescopes and an improved resolution that would allow observation of solar features heretofore not directly observable, such as magnetic flux tubes, the precursors to sunspots. The coronal loops and flares that can cause geomagnetic storms arise from sunspots; such storms can disrupt communication networks, spacecraft, and the power grid. One argument in favor of the observatory is that the ATST meets a societal need. But there are potential negative consequences of building on Haleakala. The Hawaiian petrel, an endangered seabird, nests near the proposed site, and some native Hawaiians believe that the telescope's stark white enclosure will scar a sacred area. The builders of the NSO have said they will do all they can to minimize the impact of construction on the site.

National Geographic: A record-breaking seven supernovae have been observed via interferometry in Arp 220, a highly active galaxy 250 million light-years from Earth. The heart of Arp 220 is obscured by dust that visible wavelengths can't penetrate but radio waves can. Fabien Batejat, a PhD student at Chalmers University of Technology in Onsala, Sweden, and colleagues used data from 57 of the world's largest radio telescopes to create high-resolution images of the galaxy's interior. By watching how 40 radio sources near the center of Arp 220 changed over time, Batejat and his colleagues found that seven of them were stars that had exploded around the same time. Hosting an intense burst of star formation as well as star death, Arp 220 probably behaves more like young galaxies than its local contemporaries. Batejat hopes that his team's discovery might lead to greater understanding of how stars formed and died in the early universe.

MSNBC: High-energy gamma-ray flares, with energies in excess of 100 million electron-volts, have been observed coming from the Crab Nebula since 2007. Now gamma-ray flares exceeding 100 billion electron-volts—stronger than anyone had thought possible—have been observed, and they're coming from the pulsar that spins at the nebula's heart. Nepomuk Otte, a postdoctoral researcher at the University of California, Santa Cruz, and colleagues conducted a study of the Crab's gamma-ray flares using the Very Energetic Radiation Imaging Telescope Array System (VERITAS) at the Smithsonian's Whipple Observatory in Arizona. The discovery could change scientific understanding of the process of gamma-ray emission.

Royal Swedish Academy of Sciences: Saul Perlmutter, Adam Riess, and Brian Schmidt are the winners of this year's Nobel Prize in Physics for their discovery in 1998 of the accelerating expansion of the universe. Perlmutter, who's affiliated with Lawrence Berkeley National Laboratory and the University of California, Berkeley, led one of the two independent and rival teams that made the discovery. Schmidt of the Australian National University in Canberra led the other team, which includes Riess of the Johns Hopkins University in Baltimore. Both teams surveyed a certain type of near-uniform supernovae to determine that the expansion of the universe is being driven not by mass, as had been widely assumed, but by an additional and larger source of energy. Although the source of the cosmic acceleration, which is popularly known as dark energy, remains a mystery, the acceleration itself has been confirmed by other observational methods.

BBC: The Atacama Large Millimeter Array (ALMA) in Chile has opened for astronomers, and its first image—taken with only 12 of the planned 66 radio antennas—has provided a view of the universe that can't be seen by visible-light or IR telescopes. The array of linked giant antennas sits on top of the highest plateau in the Atacama desert, close to Chile's Bolivian border. It detects wavelengths about a thousand times longer than those of visible light. The longer wavelengths allow for the study of cold objects like the clouds of dust and gas from which planets and stars form, as well as very distant objects in the early universe. One of the projects on ALMA's docket is the study of AU Microscopii, a young star about 1% the age of our Sun with a ring of matter around it that may be in the process of coalescing into planets.

Nature: Icelandic singer Björk's album Biophilia, which is released in two weeks, features songs about DNA, crystals, viruses, and electricity—each accompanied by an iPad app. Björk tells Nature's Andrew Mitchinson that the lessons are designed for children: "I felt that the years between five and eight, when a child's brain is soaking up languages and learning to read and write, are the perfect time to absorb musical theory." As part of her musical science tour, she'll be holding workshops at science museums around the globe, including in San Francisco.

Astronomy: The black hole GX 339-4, near the center of our galaxy, has a mass at least six times greater than our Sun and is orbited by a companion star that feeds it. Most of the material from the star is pulled into the black hole, but some of it is blasted outward at nearly the speed of light.

Poshak Gandhi from the Japan Aerospace Exploration Agency and colleagues have used data from NASA's Wide-Field Infrared Survey Explorer (WISE) to zoom in on the area around the base of the jet. They found that the jet's base has an average radius of about 24 000 km and that it can fluctuate by at least a factor of 10. The jet's activity also undergoes significant and dramatic fluctuations on time scales ranging from 11 seconds to a few hours. Their observations suggest GX 339-4's magnetic field is 30 000 times more powerful than that of Earth. The field provides the black hole with the necessary force to accelerate and channel the flow of matter from its companion star into a jet.

Science: Last month NSF officials met with representatives from two California-based consortia that are interested in building the next US giant ground-based telescope. The two groups—one based at Caltech, which is designing the Thirty Meter Telescope (TMT), and one at the Carnegie Institution of Science, which is working on the Giant Magellan Telescope (GMT)—may enter into competition for NSF funding of their projects. Such funding would provide more than just financial support: It could also be seen as a vote of confidence and could lead to the securing of additional funding from other partners, both public and private. However, there has been some confusion stemming from the language used in a Senate report that accompanied the proposed 2012 NSF budget; it's directed that the telescope be "developed ... on domestic soil." Because the TMT would be built in Hawaii and the GMT in Chile, some feel that the latter would be automatically disqualified. Such a qualification was not part of the National Academies' 2010 committee report, which had recommended the NSF face-off between the two projects, according to Roger Blandford of Stanford University, who chaired the committee.

The Guardian: The European Southern Observatory's High Accuracy Radial Velocity Planet Searcher (HARPS) aided in the recent discovery of 50 new exoplanets, and one of them could support life. Named HD85512b and situated in the constellation Vela about 35 light-years away, the exoplanet orbits a star at a distance that should allow liquid water to exist on its surface. The planet's mass is 3.6 times that of Earth's, and estimated temperatures range from about 30 °C to 50 °C. More than 50% of the planet would need cloud cover to be habitable. HD85512b is the second exoplanet discovered so far that could support terrestrial life.

Cosmos: "'Squeezing' laser light could significantly improve the accuracy of detectors searching for Einstein's elusive gravitational waves," writes Myles Gough for Cosmos magazine. Because gravitational waves, which are generated by violent astronomical events, have traveled billions of light-years before reaching Earth, they are greatly weakened and thus difficult to detect. Until now, the accuracy of the laser interferometers used to detect the waves has been limited by a quantum phenomenon of light called "shot noise"—a type of electronic interference. To overcome this problem, Roman Schnabel of the Max Planck Institute for Gravitational Physics in Germany and coworkers perfected a method of "squeezing" the light to reduce the noise to less than that dictated by the Heisenberg uncertainty principle and then feeding the squeezed light into the interferometer, along with the normal laser light, which resulted in a laser beam with a much more uniform intensity. "One can say that for the first time a 'technology' is based on one of the distinct features of quantum physics itself. We were able to leave the stage of laboratory experiments and realize a real application," said Schnabel. The group's results, published in Nature Physics, are an exciting step forward for the Laser Interferometry Gravitational-Wave Observatory (LIGO) project in its quest to observe gravitational waves using Earth-based detectors.

National Geographic: On a recent close flyby of Saturn's moon Dione, NASA's Cassini spacecraft revealed traces of the moon's passage left in Saturn's magnetic field—evidence of the moon's atmosphere. Dione doesn't have sufficient mass to retain an atmosphere on its own, so the thin layer of air exists only because it's constantly being replenished. The moon resides within Saturn's belt of highly energetic particles and those particles cause Dione's surface ice to break apart chemically, which releases molecules that become the moon's atmosphere. Since that ice is mostly water ice, the atmosphere may be mostly oxygen. Existing data from other Cassini instruments, as well as data gathered during the next flyby on 12 December, may provide clues to whether this is so.

Science: The Upper Atmosphere Research Satellite (UARS), sent into orbit in 1991, will return to Earth by the end of September—in about 26 pieces. NASA calculated that the odds of UARS debris injuring a human are about 1 in 3200, which amounts to about a 1 in 22 trillion chance for any one individual. The agency took into account the shape and composition of the pieces UARS would break into, and whether each piece would get hot enough to burn up on reentry; for those pieces that don't burn up, the agency calculated how far each piece could travel before impact. The total area of impact will be 22 square meters, or 236.80 square feet.

NPR: On Saturday NASA launched a pair of probes to measure the Moon’s gravity and core. Grail-A and Grail-B, part of the Gravity Recovery and Interior Laboratory mission, were launched together aboard a small Delta II rocket but will travel independently to the Moon. The probes will take a leisurely four months to reach their destination in order to save fuel, protect their instruments, and reduce the spacecraft's velocity on arrival. The Grail spacecraft, each of which is the size of a washing machine, won't land on the Moon but will conduct their research from low lunar orbit of about 55 km above the surface. "We will learn more about the interior of the moon with Grail than all previous lunar missions combined," said Ed Weiler, head of NASA's science mission directorate.

Science: A young star has been found 27 light-years from Earth in the constellation Columba. Stars are born when clouds of dust and gas collapse inward and contract; they begin to shine when they grow hot enough. At the "pre-main-sequence" stage they're powered by gravity, not nuclear activity. AP Columbae is still in this early stage; it has high lithium levels, unlike a mature star, like our Sun, whose nuclear reactions have destroyed almost all its lithium. Any planets the star possesses will be young enough to still emit detectable near-IR light, and they might show what our solar system looked like at a similar stage.

MSNBC: With the use of a powerful supercomputer, a team of researchers has produced the first realistic simulation of the formation of the Milky Way galaxy. Researchers at the University of California, Santa Cruz and the University of Zürich took advantage of 1.4 million processor-hours on NASA's Pleiades supercomputer, as well as additional supporting simulations at the Swiss National Supercomputing Center. The simulation, which took 9 months, involved tracing the motions of some 60 million particles over more than 13 billion years. According to the research team, the difficulty is in getting the simulations to match up exactly with observations. "Our result shows that a realistic spiral galaxy can be formed based on the basic principles of the cold dark matter paradigm and the physical laws of gravity, fluid dynamics, and radiophysics," said Lucio Mayer of the University of Zurich, coauthor of a paper describing the simulation, to be published in the Astrophysical Journal.

Space.com: A newly discovered galaxy 1.7 billion light-years away has captured astronomers’ attention because of its unique combination of characteristics. Speca is only the second spiral, as opposed to elliptical, galaxy known to generate large, powerful jets of subatomic particles that rush from its center at nearly the speed of light. It is also one of only two galaxies to have shown such activity in three separate episodes. The jets are produced by a supermassive black hole at Speca’s center. "This is probably the most exotic galaxy with a black hole ever seen. It has the potential to teach us new lessons about how galaxies and clusters of galaxies formed and developed into what we see today," said the study's principal investigator, Ananda Hota, of the Academia Sinica Institute of Astronomy and Astrophysics in Taiwan. Hota and colleagues have published their results in the Monthly Notices of the Royal Astronomical Society.

New Scientist: Researchers at Swinburne University of Technology in Melbourne, Australia, have detected a pulsar with an orbiting object that may be composed of diamond. Using the CSIRO Parkes radio telescope in New South Wales, Matthew Bailes and coworkers detected the pulsar in December 2009. From follow-up observations taken with the Lovell radio telescope in the UK, they surmise that the orbiting object has a mass comparable to Jupiter’s but less than half its width. The extremely fast rotation of the pulsar and the size and density of the companion object led the researchers to conclude that the object is all that's left of a star whittled down by the pulsar. Because the core of a stripped-down star would be mostly carbon, and because it would be under high pressure due to its own gravity, they believe the carbon would crystallize—most likely into diamond, much as carbon does deep inside Earth. The researchers published their results yesterday in Science.

Los Angeles Times: For the first time, astronomers say they've borne witness to a supermassive black hole consuming a star, writes Amina Khan for the Los Angeles Times. On 28 March a detector on the Earth-orbiting Swift observatory picked up a sudden burst of radiation from a point in the constellation Draco, 4.5 billion light-years away. Typically the gamma-ray bursts that Swift was designed to detect are one-time events caused by an exploding star. In this instance, however, subsequent bursts were detected from the same spot, which convinced the researchers that the origin was not a supernova exploding. David Burrows of the Pennsylvania State University and colleagues have proposed instead that a star about the same size as our Sun ended up too close to the black hole, which caused the side of the star nearest the black hole to stretch toward it, in much the same way that the Moon causes the tides on Earth. As the gravitational forces shredded the star, chunks of its plasma streamed toward the black hole, and some of the material was expelled into a jet of high-energy radiation. That jet was likely responsible for the mysterious burst detected in March. The astronomers say they were lucky to witness the event—the jet of radiation just happened to blast straight toward Swift, like a flashlight beamed in the face. Their results were published yesterday in Nature.

BBC: According to vast computer simulations of debris thrown up from asteroid impacts on Earth, more life-bearing particles could have been scattered to Mars, Jupiter, or even beyond our solar system than previously thought. Mauricio Reyes-Ruiz of the National Autonomous University of Mexico and his colleagues have carried out the largest-ever simulations of the process, which considered impacts of varying intensity. Because of new and better computing systems, the researchers were able to study the effects over much longer time periods, up to millions of years. The most important question, however, is whether any ejecta could carry living cargo. The researchers think so, as such small, hardy organisms as water bears have already demonstrated their ability to survive the harsh conditions of space. Preliminary results were presented at January’s American Astronomical Society meeting.

Telegraph: A Spanish entrepreneur has developed a helium balloon that will take space tourists into Earth’s stratosphere. With a diameter measuring 129 meters, the huge "bloon" can climb to a height of 36 000 kilometers, where the blackness of space can be seen above and the curvature of Earth below. Its pressurized cabin accommodates up to four passengers and two pilots, who spend three hours cruising, before a parachute deploys to fly the pod back to Earth. Bloon is the first project of Jose Mariano Lopez-Urdiales’s company zero2infinity, which was founded in 2009 "on a vision for a more sustainable and ethical spaceflight.” According to Lopez-Urdiales, "Going up into the earth's stratosphere in a balloon is a lot cheaper than doing it by rocket. You get to spend much more time high above and there is no engine noise." He expects to fly the first mission with people aboard in 2013.

Guardian: The Russian Express-A4M satellite disappeared hours after it was sent into orbit from the Baikonur cosmodrome in Kazakhstan, just as flight controllers began to celebrate the launch. It was later found to be still attached to its booster. Roscosmos, Russia's space agency, said that the satellite's Briz-M unit, the booster responsible for positioning it correctly in high orbit, had fired correctly over four out of five stages, but contact was lost before the final firing. The agency later located the booster and, along with it, the satellite. The A-4M's propulsion engine wasn't designed for maneuvering with extra weight; unless it's separated from the booster it will be unable to reach its designated geostationary orbit and station. The satellite, which is the largest communications satellite built in Europe thus far, was designed to provide digital television, telephone, and internet services across the former Soviet Union.

The Guardian: Lyman-alpha blobs (Lab) are gigantic clouds of hydrogen gas hundreds of thousands of light-years across. Discovered in the 1990s, they emit a bright, ethereal glow when electrons lose energy inside the hydrogen atoms, a process that produces a luminous signature known as the Lyman-alpha line. Although the light is released as ultraviolet radiation, the universe's expansion stretches the light waves so much on their way to Earth that the light appears green on arrival. Early studies showed that Labs contain clusters of young galaxies, but didn't reveal why the blobs of gas glow so brightly.

To find out, Matthew Hayes of the University of Toulouse in France and colleagues studied Lyman-alpha blob-1, which is about 11.5 billion light-years away and, at about 300 000 light-years across, several times wider than the Milky Way. They report that light from the object is polarized—the electric and magnetic fields that make up the light waves are aligned in a particular direction. It was once thought that the glow came from the hydrogen gas itself as it was pulled by extreme gravitational forces into the heart of the cloud. However, that would produce unpolarized light. The young galaxies inside Labs are stellar nurseries, and some of them have supermassive black holes at their centers. Both will likely heat up the hydrogen gas and cause it to glow. The light then becomes polarized when it's scattered through the gas cloud over distances of up to 150 000 light-years.

Space.com: NASA’s Dawn spacecraft, launched in September 2007, arrived last month at the asteroid Vesta and will spend a year circling it before moving on to arrive at the even larger asteroid Ceres in 2015. The first spacecraft to visit an asteroid in the asteroid belt between Mars and Jupiter, Dawn will study Vesta in four phases from different orbits. Each orbit should yield surface images in visible and IR wavelengths from the mapping spectrometer on board; the images will allow the science team to produce geologic and compositional maps of Vesta’s surface. Ultrasensitive measurements of the spacecraft’s motion, made using radio signals, will help researchers better understand Vesta’s gravity field. Ceres and Vesta were chosen because they are two contrasting protoplanets, Ceres being icy and Vesta rocky. Ultimately, by studying those two large bodies in the asteroid belt, researchers hope to gain more information about the formation of the solar system.

BBC: A planet about 750 light-years away in the Draco constellation has an albedo darker than coal. It reflects less than 1% of its star's light; in contrast, Earth reflects about 37% of the Sun's light and Jupiter reflects about 52%. First discovered by the Trans-Atlantic Exoplanet Survey in 2006 and named TrES-2b, the planet also lies in the Kepler space telescope's field of view. David Kipping of Harvard University and David Spiegel of Princeton University used the first four months' worth of data from Kepler to measure the amount of light coming directly from TrES-2b. The planet is only five million kilometers from its star, and its temperature is probably around 1200 °C—too hot to support reflective cloud cover. However, that is insufficient to explain the near total darkness of TrES-2b. Both Kipping and Spiegel say that something on the planet's surface must be absorbing light and that it probably involves exotic chemistry that has never been seen before.

National Journal: Tuesday’s solar flare may be responsible for knocking out high-frequency radio-communications systems in the Middle East, according to Joe Kunches, a scientist with the National Oceanic and Atmospheric Administration’s Space Weather Prediction Center. NASA, which eyeballed Tuesday's solar flare with its Solar Dynamics Observatory satellite, described it as the largest of the current 11-year solar cycle and said it was three times bigger than the previous large flare in February, writes Bob Brewin for National Journal. The Space Weather Prediction Center uses a number of satellites to develop its forecasts, which can alert people to the flares and allow them to take action to preserve power grids and other high-tech assets. Kunches, who said Tuesday’s was the largest flare since 2006, declined to predict what space weather would be like in 2013, when the current solar cycle is expected to peak.

BBC: More than 17 000 objects of a size greater than 10 centimeters currently reside in low Earth orbit. Created by humans, they consist of spent rocket stages, defunct satellites, and fragments from explosions and collisions. About 40 of the pieces are very large, weighing in at more than three tons each. Space junk is potentially hazardous to operational spacecraft, including the International Space Station. And each large piece of debris could create thousands of smaller ones if it breaks up. China's 2007 anti-satellite demonstration broke up one of that country's defunct satellites into about 2000 pieces. Such an event can start a chain reaction, in which fragments hit other fragments, which break apart, creating even more, until large areas of low Earth orbit become unusable. To clean up the mess, Marco Castronuovo of the Italian Space Agency proposes that a satellite could be launched to rendezvous with large orbiting debris and attach a propellant kit that would then drive the object into Earth's atmosphere where it would burn up. He estimates that between 5 and 10 large objects could be removed from orbit this way every year.

Indian Country Today Media Network: Possibly the only Native American astronomer in the contiguous US, Dennis Lamenti is working to recruit more Native American students into the field. Lamenti was a late comer to astronomy—he was almost 45 years old when he enrolled at San Francisco State University to pursue a bachelor’s degree in physics and later gravitated toward astronomy. Now 53, he has about two years to go on his PhD at Indiana University. Hopeful of inspiring others, Lamenti is considering a career in teaching, particularly returning home to the Navajo Nation in Arizona. He believes indigenous thought is needed for a holistic approach to science and understanding the universe, writes Michelle Tirado for Indian Country Today Media Network.

BBC: Theories predicted that the Earth's magnetic field can trap both matter and antimatter, and now data from the PAMELA instrument aboard a Russian Earth-monitoring satellite confirm this. A thin layer of antiprotons surrounds the Earth between the inner and outer Van Allen belts. The PAMELA instrument was carried into space in 2006 to study high-energy particles from the Sun and from beyond the solar system. Like other instruments in low-Earth orbit, it encounters an abundance of antiprotons when it passes through the South Atlantic Anomaly, which is an area where the inner Van Allen belt comes closest to the surface of Earth. In addition to confirming the theoretical work that had predicted the existence of antimatter bands, the belts of antiprotons could be a fuel source for future spacecraft.

NPR: To explain why the two sides of the Moon are so different from each other—the near side is low and flat and the far side is mountainous and deeply cratered—two researchers have made a novel proposition. They propose that Earth originally had two moons, the one familiar to us now and a smaller, sister moon. At some point before life on Earth began, the smaller moon collided with the larger one at a relatively low speed, which caused the smaller one to break up and spread out over the Moon’s surface, forming mountains on the far side. Erik Asphaug and Martin Jutzi of the University of California, Santa Cruz, who conducted computer simulations to test their theory, have published their results in Nature. "I think this idea is going to get a lot of attention because it's very novel, it's very clever, and people are going to be interested in testing to see whether it's right or wrong," said Maria Zuber from MIT.

BBC: The European Space Agency's Herschel Space Observatory has observed molecular oxygen in a cosmic setting. Although oxygen is the third most abundant element in the universe after hydrogen and helium, finding it in its familiar diatomic form has proven difficult—until now. Paul Goldsmith of the Jet Propulsion Laboratory and his collaborators have taken advantage of Herschel's 3.5-meter sintered silicon carbide mirror and its high-resolution far-IR spectrometer to identify the spectral signature of vibrationally excited O₂ molecules in the Orion Nebula, a region of active star formation. Goldsmith and his coauthors report their findings in a paper to appear in the Astrophysical Journal. They speculate that the O₂ was originally stuck to dust grains and incorporated into pieces of dirty ice. Starlight then baked off the O₂.

National Geographic: Earth's first Trojan asteroid, 2010 TK7, has been discovered. About 1000 feet wide, it travels with Earth around the Sun at a distance of about 50 million miles, writes Ker Than for National Geographic. Trojans are bodies that exist in orbital "sweet spots" between Lagrange points—spots where the gravitational pull of the planet and that of the Sun combine to allow the Trojan to maintain its position relative to both of them. Trojan asteroids have been found around Mars, Jupiter, and Neptune; although it had long been thought that Earth should also have them, they proved difficult to find because any Trojan, from the perspective of an observer on Earth, will reside in the general direction of the Sun. Martin Connors, an astronomer at Athabasca University in Canada, and colleagues made the discovery with NASA's Wide-field Infrared Survey Explorer (WISE) telescope. Connors likened the asteroid's orbit to the path of an orange held at arm's length by a person riding a Ferris wheel.

Science: Evidence suggests that the now quiescent, supermassive black hole at the center of the Milky Way experienced a period of intense activity a few million years ago that produced some of the highest-energy radiation in the universe. A pair of gamma ray-emitting gas bubbles that seem to have been fueled by a violent event at the galactic core were discovered last year, along with more newborn stars and less elderly stars than had been expected, writes Ron Cowen for Science. Kelly Holley-Bockelmann of Vanderbilt University and her colleagues say this activity may have been caused by a collision between the Milky Way and the remains of a satellite galaxy that housed an intermediate-mass black hole. Gas orbiting within the innermost 5000 light years of the galaxy would have been pushed into the center, and some of that would have fallen into the central black hole and generated the gamma ray-emitting gas bubbles. Part of the gas would have become raw material for the young stars that have been observed there, and the Milky Way's black hole and the satellite's smaller one could have propelled old stars outward from the center as the two black holes merged. If that was the case, the outward-flung stars would have formed a ring of high-velocity stars a few thousand light-years from the center, and they could be detected by the Hubble Space Telescope.

Science: On 18 July the Russian orbital radio telescope Spektr-R was finally launched, writes Daniel Clery for Science. Originally designed in 1982, the satellite was put on hold following the collapse of the Soviet Union. The goal of the Russian satellite is to work with ground-based radiotelescopes to create images of unprecedented precision. Spektr-R aims to study the structure and dynamics of radiosources both inside and beyond our galaxy, shedding light on the structure of galaxies, star formation, black holes, dark matter, and interstellar space.

NASA: Scheduled to launch late this year, NASA's next Mars rover, Curiosity, will land at the foot of a mountain inside the planet's Gale crater sometime in August 2012. “Curiosity not only will return a wealth of important science data, but it will serve as a precursor mission for human exploration to the Red Planet,” said NASA administrator Charles Bolden. Researchers will use the rover's tools to study whether the landing region had favorable environmental conditions for supporting microbial life and for preserving clues about whether life ever existed. To choose the site, more than 100 scientists considered the safety concerns and scientific attractions of some 30 different locations.

NASA: Some 5 billion km from Earth, a fourth moon has been found orbiting Pluto. Using the Hubble Space Telescope, astronomers discovered it while they were searching for rings around the icy dwarf planet. The new moon, temporarily designated P4, is Pluto’s smallest, with an estimated diameter of 13–34 km. By comparison, Pluto’s largest moon, Charon, is 1043 km across, and Nix and Hydra are each 32–113 km across. "This is a fantastic discovery," said Alan Stern of the Southwest Research Institute in Boulder, Colorado. Stern is principal investigator of NASA’s New Horizons mission, scheduled to fly through the Pluto system in 2015. "Now that we know there's another moon in the Pluto system, we can plan close-up observations of it during our flyby," he said.

Space.com: A physicist at the UK’s University of Warwick believes he has found a testable explanation for apparent CP violation. In a paper published in Europhysics Letters, Mark Hadley suggests that researchers have neglected to take into account the significant impact of the rotation of our galaxy on the pattern of how subatomic particles break down. He thinks that although matter and antimatter versions of the same particle begin as mirror images of each other, as they decay they experience what he terms galactic “frame dragging,” whereby the speed and angular momentum of the galaxy twist the space and time around it. The effect is significant enough to cause the different structures in each particle to experience different levels of time dilation and therefore decay in different ways. "This radical prediction is testable with the data that has already been collected at [the Large Hadron Collider at] CERN and BaBar [at SLAC] by looking for results that are skewed in the direction that the galaxy rotates," Hadley said.

Astronomy: Most, if not all, large galaxies have a supermassive black hole in their center. In many galaxies, including the Milky Way, that black hole is quiet. In some galaxies, though, material falls into the black hole, giving off intense radiation as it does so. Until now, astronomers believed that this material was the result of two galaxies either merging or passing each other closely enough to disrupt some galactic material, which would then fall into the black hole, creating an active galactic nucleus. New data from the European Southern Observatory's Very Large Telescope and the European Space Agency's XMM-Newton x-ray space observatory indicate that this is not actually the case for most galaxies. Viola Allevato, of Germany's Max Planck Institute for Plasma Physics in Garching, and colleagues have examined data for more than 600 active galaxies, and they found that most active galactic nuclei are fed by processes within the galaxy itself, such as disk instabilities and starbursts, rather than by galaxy collisions or mergers.

The Guardian: The planet Neptune was discovered not by astronomers but by mathematicians, who theorized that the orbit of Uranus was shaped by the gravity of another planet even farther from the Sun than Uranus. The mathematicians, John Adams and Urbain Le Verrier, came to their conclusions separately in 1846. While Adams tried to get astronomer royal George Airy to look for the planet, Verrier announced his prediction publicly. Astronomers in Berlin looked where Verrier had suggested and found Neptune; 10 days later, William Lassell, a Liverpool brewing magnate, took a look and found not only Neptune, but a white "star" close by. He had discovered Triton, one of Neptune's moons. Yesterday marked the first Neptunian anniversary of its discovery 164.79 (Earth) years ago: one full turn of the planet around the Sun.

Space.com: The final space shuttle launch took place this morning. NASA's Atlantis began its 12-day mission to the International Space Station with a successful lift-off from Florida's Kennedy Space Center around 11:26am EDT. Some 750 000 to 1 million eager spectators showed up for the historic event. The four-astronaut crew will deliver about 9500 pounds of cargo and several science experiments to the station. "Good luck to you and your crew on the final flight of this true American icon. Good luck, Godspeed, and have a little fun up there," shuttle launch director Mike Leinbach told the astronauts just before launch.

New York Times: With the aid of the European Space Agency’s Herschel Space Observatory, researchers have studied a massive cosmic dust reservoir created by a supernova almost 25 years ago, writes Sindya Bhanoo for the New York Times. “We are looking at the sky at wavelengths that have never been observed before,” said Mikako Matsuura, an astronomer at University College London and lead author of a study published in Science. The supernova occurred some 160 000 light-years away when an aging star’s core collapsed. Matsuura and her team reported that the explosion generated enough cold dust to form more than 200 000 Earths. By studying the dust using Herschel and other telescopes, the researchers hope to better understand how galaxies, including the Milky Way, are formed.

Sydney Morning Herald: Australia is one of the shortlisted candidates to host the Square Kilometer Array (SKA) telescope, the world's most powerful radio telescope. The final decision is expected in February. One potential problem for Australia's bid is that the SKA requires a 30-kilometer, or 18.6-mile, area of "radio quiet" to function properly; radio signals from human activity can overwhelm radio-wave signals from space. Its prospective location in Western Australia is close to mining operations that rely on radio communications. Brian Boyle, of the Commonwealth Scientific and Industrial Research Organisation, is leading Australia's bid for SKA and believes the mining and scientific sectors can coexist in the region.

New Scientist: Yesterday, in a draft 2012 budget for NASA and other government agencies, a congressional committee proposed canceling the James Webb Space Telescope. The Commerce, Justice, Science, and Related Agencies Subcommittee, which creates a draft budget for NASA each year, announced in a press release that it proposed to terminate funding because the telescope "is billions of dollars over budget and plagued by poor management." To go into effect, the draft budget will need to be approved by the entire Appropriations Committee, the House of Representatives, the Senate, and President Obama.

Nature: A demographic analysis shows that NASA's cohort of experienced, highly qualified principal investigators (PIs) able to lead Discovery-class missions—a series of focused planetary science projects to explore the solar system—is nearing retirement age. Susan Niebur first noticed the demographic shift when she ran the Discovery program at NASA between 2003 and 2006. As an independent consultant she has continued to track the dwindling number of experienced PIs; by 2015, only 14 potential PIs out of a likely 30 will have experience as PIs, deputy PIs, or project scientists. If NASA doesn't find a way to give younger scientists opportunities to develop the necessary experience to step into mission-leading roles, the program as a whole may suffer from PI burnout, missed launch windows, and cost overruns. However, an inexperienced PI doesn't necessarily doom a mission to failure. Most of the program's missions have succeeded, including those led by less experienced PIs.

BBC: Unexplained "filaments" of radio-wave emission close to our galaxy's center may hold proof of the existence of dark matter, writes Jason Palmer for the BBC. First discovered in the 1980s, the filaments are known to be regions of high magnetic fields, and they emit high-frequency radio waves. Now Dan Hooper at Fermilab and colleagues have posted a paper on the arXiv e-print server suggesting that the filaments' emission arises from dark-matter particles crashing into each other. And the electrons created in those crashes could be responsible for the synchrotron radiation detected here on Earth. The researchers claim that the theory can explain many of the different features that are observed in the filaments' emission, such as the brightness of the filaments closer to the galactic center compared with those farther away—there's more dark matter closer to the galactic center. Nevertheless, several other ideas that do not invoke dark matter could account for the filaments; more observations using more radio telescopes are needed.

Astronomy: On 23 June NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA) observed Pluto's passage in front of a distant star. Planetery occultations—when a star is hidden by a planet that passes between it and the observer—that involve Pluto allow astronomers to study the dwarf planet's atmospheric pressure, density, and temperature profiles. SOFIA is a modified Boeing 747SP aircraft carrying a 100-inch telescope; it operates in the stratosphere and is thus able to make observations unhindered by the water vapor in Earth's lower atmosphere. The mobile observatory flew from its base in southern California to intersect Pluto's shadow as it traveled across the Pacific Ocean and was able to place itself to maximum advantage, in the center of the planetary shadow.

Science: Many planets with an atmosphere have a faint illumination or glow that can be seen on the horizon. Apollo 8 astronaut James Lovell saw something similar when his spacecraft went around the Moon in 1968, but the Moon has no atmosphere to catch the Sun's rays and create such a spectacle. Data collected by the Lunar Ejecta and Meteorites (LEAM) experiment, placed on the Moon in 1972, suggested that lunar dust was picking up an electric charge from cosmic rays or the solar wind to drive it high into the lunar sky and cause the glow. But now former Apollo physicist Brian O'Brien, who helped design dust monitors for several of the Apollo spacecraft, argues in Planetary and Space Science that much of the LEAM data were not detections of charged lunar dust particles but instead electrical interference generated by the Apollo Lunar Surface Experiments Package (ALSEP) instruments parked 7.5 meters away from LEAM. A final answer may be provided by NASA’s Lunar Atmosphere and Dust Environment Explorer, which launches in 2013.

Wired: For the first time, physicists have watched a single proton flip over on its axis. Aside from being a technical triumph, the measurement may eventually help determine why the universe contains more matter than antimatter. When matter and antimatter meet, they annihilate each other. One possible explanation for the predominance of matter, opposite charge aside, is that antimatter isn't always truly identical to matter. To determine if this is true, physicists need a way to compare matter and antimatter. In a study published 24 June in Physical Review Letters, physicists take an important step toward comparing protons and antiprotons by measuring the magnetic moment.

The magnetic moment is a description of how a magnetic field pulls on a particle. Stefan Ulmer of the Helmholtz Institute Mainz in Germany and colleagues showed that it’s possible to measure the magnetic moment of a single proton — and by extension, a single antiproton — by watching it flip back and forth. They accomplished this by confining one proton in a tiny vacuum called a Penning trap. A proton usually aligns its magnetic poles with the trap’s magnetic field, pointing its northern end upward. But adding an extra magnetic field that spirals in from the side makes the proton do a somersault, pointing its northern end down. How quickly the proton wobbles as it somersaults is proportional to the strength of its magnetic moment.

Now that they know how to measure the magnetic moment of a single proton, the researchers plan to take their device to CERN and try it on antiprotons.

Washington Post: Scientists now believe that Saturn's moon Enceladus may have a vast ocean beneath its surface. Measurements taken by the Cassini-Huygens spacecraft during 2008 and 2009 flybys have shown large grains of ice with substantial amounts of salt spewing from the bottom of the moon. Frank Postberg of the University of Germany, lead author of a study published today in Nature, and colleagues think the ice grains are coming from surface fractures at the moon's southern pole, areas that have been deemed "tiger stripes." That the stripes are the apparent source of salty ice is considered a significant breakthrough with implications for understanding planets and moons and for detecting possible sites hospitable to life, writes Marc Kaufman for the Washington Post.

CNN: Using NASA's Chandra X-ray Observatory, scientists have determined that at least 30 million black holes had formed before the universe was 1 billion years old, quite early in the universe's 13.7-billion-year history, writes Elizabeth Landau for CNN. Black holes are dense regions in space that have collapsed in on themselves; material in their vicinity gets drawn in, and as they devour that matter, they emit x-ray radiation. No one knows how the first black holes were formed after the Big Bang, nor which came first: the galaxy or the black hole. The Chandra observations indicate that proto-galaxies already had central black holes, but black holes and their galaxies appear to be growing together. In addition, "all the black holes we see at the centers of galaxies today are in a way descended from those baby black holes we see at the dawn of the universe," said Kevin Schawinski of Yale University and coauthor of a study published in Nature. He and his coworkers plan to push even further into the early universe to gain more insights into the early black holes.

Space.com: Launched in 2007 to study Vesta and Ceres, the two most massive members of the asteroid belt, NASA’s robotic spacecraft Dawn is already sending back scientifically significant photos of Vesta, even though the spacecraft is not scheduled to enter the second largest asteroid’s orbit until next month. The images reveal several intriguing features, including a dark blotch about 97 km wide near the equator of the 530-km-wide Vesta. Dawn will orbit and study Vesta for one year, then move on to investigate the dwarf planet Ceres. Dawn will be comparing the two giant bodies, which were shaped by different forces, and scientists hope it will help unlock the secrets of our solar system’s early history.

National Geographic: The heliosphere, our solar system's magnetic barrier, was once thought to be a smooth shield but may instead be a sea of long magnetic bubbles that function more like a porous membrane than an impermeable shield. Galactic cosmic rays and energetic particles can become trapped in the membrane, but they will eventually make their way along solar magnetic field lines toward the Sun, writes Ker Than for National Geographic. The new theory is based on data from NASA's twin Voyager spacecraft launched in 1977; both recorded dramatic variations in the amount of electrons they encountered as they traveled through the heliosphere. A NASA computer model suggests that the fluctuating readings may have been the result of the spacecraft entering and exiting magnetic bubbles, which would act as electron traps—causing higher than normal electron bombardment of spacecraft passing through them.

New Scientist: China has started building the world’s biggest and most sensitive radio telescope—the Five-hundred-meter Aperture Spherical Radio Telescope, an instrument that promises to transform radio astronomy, writes Anil Ananthaswamy for New Scientist. The instrument, which will be located near the city of Duyun in Guizhou Province, will allow astronomers to peer three times farther into the universe than any previous telescope. Although its dish will be fixed in an 800-meter-wide karst—a sinkhole formed by eons of water eroding limestone bedrock—a series of large motors will be able to change the shape of the dish’s reflective surface, allowing it to scan large swaths of the sky.

Nature: The spacesuits worn by the first astronauts are being moved from their current home in Maryland to the Smithsonian's Steven F. Udvar-Hazy Center in Chantilly, Virginia. While the new facility will provide a much better environment for the suits, getting them there intact was a puzzle for conservators, writes Nicola Jones for Nature. Lisa Young, one of the conservators working on the project, came up with a unique solution: transport the suits in retrofitted coffins used by the airline industry. She and her colleagues lined the coffins to make them waterproof and equipped them with seat belts so the suits wouldn't move in transit. The suits' new home will keep them—along with the space shuttles Enterprise and Discovery and roughly 1200 other items such as spare spacesuit gloves, memorabilia, trophies, and artwork—under one roof with lab facilities for visiting scientists and the staff conservators. The conservation work and storage in the newer facility should allow the suits to last another 50 years—a significant improvement over the 20 more years they would likely have lasted otherwise.

Nature: When stars several times more massive than our Sun die, they explode into supernovae, radiating enough energy to outshine a galaxy. The radiation is sometimes produced by radioactive decay, and sometimes by the explosive release of heat, or from a collision between debris ejected by the star and material surrounding it. Six such explosions can't be explained by any known process, writes Jon Cartwright for Nature. Robert Quimby of Caltech and colleagues think that these explosions should be classified as a new type of supernova. All six explosions are about 10 times more luminous than type Ia supernovae (the most commonly recorded type), and unlike most supernovae, their main emission is UV radiation rather than visible light. Quimby's team has theorized that the exploding stars may have been so large that they became unstable and threw off bits of material before finally going nova. That material would then interact with the final explosion, causing the intense brightness. On the other hand, the supernovae might, in their early stages, have become magnetars—spinning, highly magnetized neutron stars. The very strong magnetic field of such stars would slow down their spin, and the excess energy of their motion may have been released to make them unusually bright.

Wall Street Journal: Two scientists share this year’s Shaw Prize in astronomy: Gerald Fishman, chief scientist at NASA’s Marshall Space Flight Center, and Enrico Costa, director of research at the Italian National Institute of Astrophysics. According to a press release, the two men were picked "for their leadership of space missions that enabled the demonstration of the cosmological origin of gamma ray bursts, the brightest sources known in the universe." The Shaw Prize, Hong Kong’s equivalent of the Nobel Prize, annually recognizes innovation in three fields—astronomy, medicine, and mathematics—with three awards of $1 million each.

NPR: The James Webb Space Telescope will cost about $6.5 billion, rather than the $5 billion NASA had planned to spend, and the launch date has been pushed forward from 2014 to 2018. Nevertheless, enthusiasm remains high for the massive IR telescope, writes Nell Greenfieldboyce for NPR. It will detect longer wavelengths of light than the Hubble Space Telescope and will likely revolutionize astronomy as much as the Hubble has done over the last two decades. It will search for the first galaxies formed after the Big Bang, search for water on planets orbiting distant stars, and help astronomers determine how galaxies evolve. Part of the reason for the cost overruns is that the technologies necessary for the telescope's operation needed to be invented and it's difficult to estimate those costs up front. As large as a Boeing 737, the telescope must fold up to fit inside a rocket for its journey 1 million miles into space—and then unfold once it reaches its destination. But JWST isn't the first such project to have an unexpected increase in cost; when Hubble was launched, it cost about three times as much as had originally been estimated.

Science: There may be 10 times as many extrasolar planets suitable for advanced life as previously thought, writes Govert Schilling for Science. A new study by Jack Lissauer of NASA’s Ames Research Center in California and colleagues contradicts the notion that a terrestrial planet needs a large moon to stabilize the orientation of its axis and therefore its climate. The axial tilt of Mars, which has only two tiny moons, has varied between 10° and 60° in the past, which caused a tremendous variation in climate. However, Lissauer’s study demonstrates that such climate variations would take place over billions of years—giving life plenty of time to evolve.

Washington Post: Six years ago, the Japanese spacecraft Hayabusa landed on the near-Earth asteroid 25143 Itokawa and retrieved a sample. A capsule containing the sample landed on Earth last summer. NASA has just announced plans for a similar mission. In 2016 the billion-dollar OSIRIS-REx spacecraft will begin its four-year journey to the near-Earth asteroid RQ36. Once OSIRIS-REx is in orbit around the asteroid, mission planners will identify a suitable landing site. As the Washington Post's Brian Vastag explains, planetary scientists want to analyze asteroid material because of its possible relevance to the origin of life on Earth. Ground-based spectroscopic measurements indicate that RQ36 contains carbon-bearing materials. If the same materials made it through the asteroid belt and landed on Earth, they might have provided a key ingredient for life, carbon.

Astronomy: The highest-resolution image of galactic jets has been produced by the Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry (TANAMI) project. The new image shows a region less than 4.2 light-years across, and radio-emitting features as small as 15 light-days are visible. Using an international array of nine radio telescopes located throughout the Southern Hemisphere, researchers for the TANAMI project combined the data from each one into a large, highly detailed image of Centaurus A, also known as NGC 5128, a nearby galaxy with a supermassive black hole. It's one of the brightest objects in the sky when seen in radio waves; this is because the visible part of the galaxy sits between two radio-emitting lobes, each nearly one million light-years long, that are filled with matter streaming from particle jets near the black hole. The jets are formed when some of the matter falling into the black hole is ejected at about one-third the speed of light. They may change the rate of star formation within a galaxy, thus playing an important role in galactic evolution.

BBC: An international team of astronomers has used the results from a major astronomical survey to confirm the existence of dark energy, estimated to make up about 74% of the total mass–energy of the universe. The WiggleZ Dark Energy Survey, which was carried out August 2006–January 2011, used data from NASA’s Galaxy Evolution Explorer and the Anglo-Australian Telescope to map the distribution of some 200 000 galaxies and look back in time about 8 billion years. The astronomers used two separate kinds of observation to provide an independent check on previous dark-energy results, writes Paul Rincon for the BBC. The concept of dark energy was first invoked in the late 1990s to reconcile the measured geometry of space with the total amount of matter in the universe and to explain why the universe appears to be expanding at an accelerating rate.

Nature: Today a team of scientists in Europe released the results of a €3 million ($4.3 million) design study on the Einstein Telescope (ET), writes Eugenie Samuel Reich for Nature. The telescope, scheduled to be constructed around 2025, would represent the third generation of gravitational wave detectors. The first generation includes the US's Laser Interferometer Gravitational-Wave Observatory (LIGO), already in operation, and the second includes Advanced LIGO, which will not go online until around 2015. The €1 billion ($1.4 trillion) ET observatory will continue the search for gravitational waves and their sources, thought to include such dramatic astrophysical events as the merger of black holes or neutron stars. Such large ripples in spacetime, which were first predicted by Einstein's theory of general relativity, have yet to be directly detected. The new telescope, which will be 10 times as sensitive as Advanced LIGO, also offers the potential to probe the earliest moments of the universe just after the Big Bang.

Science: A long-running debate on whether free-floating planets really exist and how common they are may now be resolved, writes Jon Cartwright for Science. A new study by Takahiro Sumi of Osaka University in Japan and colleagues lists 10 objects in our galaxy that are very likely "homeless" planets and posits that such planets are more common than main-sequence stars, outnumbering them by nearly two to one. The team used a technique called gravitational microlensing to measure changes in the brightness of distant stars, whose light is bent and magnified by the gravity of planets passing in front of them. Smaller planets create shorter magnification times. The team found 474 incidents of microlensing, just 10 of which were brief enough to be planets of around Jupiter's size, while the other 464 microlensing events were due to bigger objects such as brown dwarfs. One question arising from the study is how the free-floaters formed. According to one explanation, they used gravity to draw in nearby material such as the asteroids and protoplanets in our solar system. Sumi and his colleagues think it's more likely that they began their lives in planetary systems and were subsequently thrown out of orbit.

Ars Technia: The red dwarf Gliese 581, only 20 light years from Earth, is host to at least five planets, three of which have been considered potentially habitable. The latest addition to this list is GJ581d, writes John Trimmer for Ars Technica. The planet is a super-Earth that was previously thought to support neither liquid water nor enough of an atmosphere to produce a significant greenhouse effect. Although GJ581d lies at the far edge of the star's habitable zone, it's still close enough for tidal locking to ensure that only one side of the planet ever faces the star. The planet's poles and far side are therefore extremely cold; below a certain temperature an atmosphere collapses as its constituents freeze out. Robin Wordsworth of the Institut Pierre Simon Laplace in Paris and colleagues have developed a general circulation model (GCM) that can be applied to a range of planets. In the case of a planet like GJ581d, the team found that denser atmospheres lead to horizontal heat transport and a greenhouse effect strong enough to keep the atmosphere intact and allow for surface temperatures above the melting point of water. Although it's not known whether GJ581d has a dense atmosphere, Wordsworth and his team have devised a test. Using their model, the team synthesized emission spectra that could be compared to real spectra once they become available.

BBC: Tardigrades, also known as water bears, joined the crew of the space shuttle Endeavour on Monday as part of Project Biokis, sponsored by the Italian Space Agency. The project will investigate the impact of short-duration spaceflight on several different microscopic organisms; Tardkiss, a subset of the project, will expose tardigrade colonies to different levels of ionizing radiation at different points during the spaceflight. The data will be used to help determine how radiation dosage affects the way cells work. Less than one millimeter long and ubiquitous on Earth, water bears became the first animals to survive exposure to space during the European Space Agency's 2007 Foton-M3 mission. In inhospitable conditions, they enter a state of dormancy called cryptobiosis—an ametabolic state that allows them to resist physical and chemical extremes, including solar winds, high pressure, and the vacuum of space. The Tardkiss study may facilitate the development of techniques to protect other organisms, including humans, from the extreme stresses encountered during space exploration.

LA Times: The space shuttle Endeavour blasted off to its final mission today, carrying the Alpha Magnetic Spectrometer (AMS-02), two communications antennas, a high-pressure gas tank, additional parts for the Dextre robot, and other critical supplies to the International Space Station. Endeavour's crew will also transfer the shuttle's orbiter boom sensor system to the ISS, where it can assist spacewalkers as an extension for the station's robotic arm. The 16-day mission includes four spacewalks for the shuttle crew, with the return to Earth scheduled for 1 June. The AMS-02 will operate as an external module on the ISS for a nominal mission of 3 years, gathering data at 7 gigabits per second. It will analyze cosmic rays and flux and search for antimatter and dark matter; it will continue to provide cosmic-ray measurements after its nominal mission is complete.

BBC: Io, one of Jupiter's moons, is the most volcanic body in the solar system; it erupts 100 times more lava a year than does Earth, writes Jonathan Amos for BBC News. A reassessment of data from NASA's Galileo probe suggests that this is due to a reservoir of magma at least 50 kilometers thick that probably makes up at least 10% of the moon's mantle by volume. Unlike Earth, where volcanoes tend to collect at the boundaries of tectonic plates, Io has volcanoes all over its surface. Jupiter drives this volcanism by producing tides on the moon that squeeze and pull Io's body, melting its rocks. In turn, Io dramatically distorts Jupiter's magnetic field, although it wasn't until several years after Galileo made its passes of the moon that physicists were able to determine why. The conductivity of rocks high in magnesium and iron increases by orders of magnitude when they melt; that conductivity was what allowed Io to influence its parent planet's magnetic field so strongly.

Space.com: Next August, if all goes to plan, NASA's car-sized rover Curiosity will touch down on the Martian surface and begin its mission: to determine whether Mars is or was ever hospitable to life. The person responsible for the mission's success is project manager Peter Theisinger of the Jet Propulsion Laboratory in Pasadena, California. In a Q&A with Space.com's Mike Wall, Theisinger describes the technical challenges he and his colleagues had to contend with, notably ensuring that the rover lands safely and upright. Comparing Curiosity with its two famous predecessors, Theisinger answered,

Spirit and Opportunity were geology missions. They were looking for signs of water, and they found it. This is taking the next step forward: to look at more detailed chemistry and mineralogy, and to see if there were true habitability possibilities, and to search for organics as well.

Science: The thick nitrogen-rich atmosphere of Saturn's largest moon, Titan, may have been blasted into existence 3.8–4 billion years ago, during the appropriately named Late Heavy Bombardment period. Most planets and moons in the solar system were pounded by large numbers of comets, asteroids, and other large objects at that time, and they may have impacted Titan's surface with enough energy to chemically strip apart the ammonia-rich ice there. Yasuhito Sekine, a scientist at the University of Tokyo in Kashiwa, Japan, and colleagues tested this hypothesis by firing tiny, laser-accelerated particles of gold, platinum, and copper at various speeds into mixtures of frozen ammonia and ice. Their experiments suggest that the heat and pressure generated at impact speeds greater than 5.5 kilometers per second are enough to break down ammonia ice into nitrogen, hydrogen, and water vapor. If Titan had a primordial atmosphere, it would have been destroyed by the bombardment and replaced with ammonia-derived nitrogen. If it had no atmosphere to begin with, the number and size of impacts expected for the moon would have been sufficient to generate the amount of nitrogen that exists in its atmosphere now.

National Geographic: A planet close to Earth's size and in orbit around a Sun-like star, 55 Cancri e has the density of lead and is the hottest known rocky world. Residing in a five-planet system within the constellation Cancer, 55 Cancri e is 42 light-years away. First discovered in 2004 via ground-based telescopes, the planet's orbit has now been shown to be 17 hours and 41 minutes long, one-quarter of the original estimate of 2.8 days. This February, Jaymie Matthews of the University of British Columbia and colleagues used Canada's Microvariability and Oscillations of Stars (MOST) space telescope to measure the tiny dips in starlight as the planet passed in front of its star. Its 17-hour orbit means that it's about 20 times closer to its star than Mercury is to Sol. The brightness of the host star meant that MOST was able to determine the planet's size and mass—60% larger and eight times more massive than Earth. Astronomers' understanding of the planet is still developing; just this week, a second team independently reported that the planet's radius may be up to a third larger than the value reported by the MOST team. Both teams agree that whatever its actual radius, 55 Cancri e is a new class of planet.

BBC: The European Space Agency is planning a replacement for its Automated Transfer Vehicles (ATVs), and it would like NASA to be involved. Since 2008, the unmanned ATVs have been taking supplies to, and trash from, the International Space Station. The ATVs are expendable. After leaving the ISS, they follow a course that results in their burning up in Earth's atmosphere. Now that only three more ATVs remain in production, ESA has entered discussions with NASA to jointly develop a spaceship based on the ATV.

Science: Gravity Probe B, launched in 2004, has confirmed two predictions derived from Einstein's theory of general relativity. The satellite, which circled Earth from pole to pole for 17 months, used gyroscopes to measure the geodetic effect caused by Earth's mass creating a dimple in spacetime; the circumference of a circle around Earth should be slightly shorter than 2π times the circle's radius. Gravity Probe B measured the 2.8-centimeter decrement to 0.25% precision. The satellite's measurement of the frame-dragging effect, in which Earth twists the surrounding spacetime as it rotates, fell short of expectations and achieved 19% precision. The gyroscopes were geometrically the roundest objects ever manufactured—but trapped charges in their niobium coating made them far less precisely round electrically. Those imperfections combined with ones in the gyroscope's housing to create uncertainties that took five years to correct. In 2004 Ignazio Ciufolini (University of Salento in Lecce, Italy) and colleagues used data from less expensive satellites, LAGEOS and LAGEOS II, to measure the frame dragging effect to 10% precision. Whether Gravity Probe B merely confirms those results, or has additional importance, is a matter of perspective.

Nature: China plans to deploy its own space station by 2020 as a key part of its human spaceflight program. The proposed three-person station, which will be smaller in mass than either the International Space Station or Russia's Mir, will consist of an 18.1-meter-long core module, two 14.4-meter experimental modules, a manned spaceship, and a cargo craft. Official state media confirmed that the Tiangong 1 and Shenzhou 8 unmanned space modules will attempt docking in orbit later this year; that maneuver is essential for assembling a station in orbit. If the docking is successful, China will proceed with construction by launching additional modules over the next decade.

Scientific American: The search for extraterrestrial intelligence (SETI) lost ground last month when funding for the Allen Telescope Array ran out. Built by the SETI Institute and operated by the University of California, Berkeley, the ATA is a field of radio dishes in rural northern California designed to seek out transmissions from alien civilizations. Tom Pierson, CEO of the SETI Institute, announced to donors on 22 April that the ATA has been put into “hibernation,” meaning that "starting this week, the equipment is unavailable for normal observations and is being maintained in a safe state by a significantly reduced staff." The nonprofit SETI Institute, founded in 1984, relies on private donations to support its research. Pierson said that the institute has been investigating other sources of revenue, such as working out a deal with the US Air Force whereby the ATA could assist in tracking orbital debris that can endanger defense satellites.

Space.com: A liquid-water ocean may lie beneath the icy surface of Saturn’s moon Titan, according to new evidence collected by NASA’s Cassini spacecraft, writes Mike Wall for Space.com. In orbit around Saturn since 2004, Cassini has provided considerable data, including information about Titan’s rotation and orbit. The new data reinforce earlier suppositions about a possible below-surface ocean. In a new study that will appear in the journal Astronomy and Astrophysics, lead author Rose-Marie Baland of the Royal Observatory of Belgium in Brussels and colleagues theorize that Titan is not a completely solid body, but rather that it has a solid interior surrounded by a liquid-water ocean and all enclosed in an icy shell. In addition, the possible presence of water leads the researchers to believe that Titan could support some form of life. "Astrobiologists do not really know yet what are the necessary conditions for life to emerge, but it seems that the presence of water is a requirement," said Baland.

Nature: Since the 1960s, probes with heated tips have been used to bore through ice, but they have their problems and limitations: Dirt and sediment would often build up at the head of the probe and impede the transfer of heat, and most of the probes could only move downward through layers of ice. After two years of work, Bernd Dachwald, of Aachen University of Applied Sciences in Germany, and colleagues have developed IceMole, a new type of ice-melting probe that is capable of pulling itself through ice layers—not only downward but also horizontally and upward. A 6-cm screw at its head allows the probe to keep in contact with the ice it is trying to melt. The probe easily penetrates dirt and should also be able to function where the ice is in a near vacuum. A French team has already expressed interest in using the probe to search for micrometeorites in ice; it could prove useful for everything from sampling Antarctic subglacial lakes to searching for indications of subsurface water on icy outer moons such as Europa.

Physics Today: The final launch of the space shuttle Endeavour, scheduled for today, has been delayed for at least 48 hours because of a problem with the heaters associated with the shuttle’s auxiliary power unit, according to Manuel Roig-Franzia writing for the Washington Post. Officials at first thought the weather would cause a delay, but forecasters predicted the skies would clear in time. Endeavor is scheduled to deliver the Alpha Mass Spectrometer (AMS-2), the "first fundamental science experiment to the International Space Station," says Nobel Prize winner Samuel Ting, AMS-2's principle investigator. The $2 billion experiment, a collaboration between more than 40 institutions and 600 physicists, has taken more than 17 years to reach this point and has suffered dramatic setbacks, including the loss of its ride to the space station following the space shuttle Columbia disaster in 2003 and the last-minute replacement last year of its superconducting magnet with a less powerful permanent magnet.

AFP: Anatoly Perminov will be replaced as head of the Russian space agency Roskosmos after a series of high-profile mishaps. Vladimir Popovkin, currently first deputy defense minister, will replace him. Although Perminov had reached the maximum age for state employees, there have been clear indications of government frustration with Roskosmos's performance for some time. The latest manned launch for the International Space Station was delayed in March, less than a month before the 50th anniversary of Yuri Gagarin's first spaceflight. In February, the Geo-IK-2 military satellite was rendered useless for defense when it was put into the wrong orbit. And in December, a fuel miscalculation caused three navigation satellites for the new Russian GLONASS system to crash into the ocean off Hawaii instead of reaching orbit. In February, Deputy Prime Minister Sergei Ivanov issued a scathing assessment of Roskosmos's performance, saying that the GLONASS mishap was characteristic of its problems and that any repeat satellite failure would be unacceptable. Perminov has served as Roskosmos chief since March 2004.

Science: The first stars, formed about 300 million years after the Big Bang, are thought to have been hundreds of times bigger than the Sun. According to a new study, they also whirled at incredible speeds of about 500 km/s—250 times faster than the Sun does. While it is unlikely that those stars could be detected directly, the velocity of their rotation probably led to their ending their lives with a gamma-ray burst (GRB), which produces a huge flash of high-energy radiation. GRBs can be detected from much farther away than individual stars. NASA is considering a small explorer mission; its Joint Astrophysics Nascent Universe Satellite could give astronomers the means to observe GRBs created by primordial stars in their final moments.

Ars Technica: The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory has produced the heaviest antimatter particle ever seen in a laboratory: antihelium-4, the antimatter partner of the alpha particle. Antihelium-3 was detected in the 1970s, but the antialpha has proved more difficult to spot. For a nucleus to condense, the right number of antimatter baryons of the right types must be traveling near enough to one another, with similar enough momenta. By colliding gold atoms, which each have 79 protons and 118 neutrons, RHIC increased the chances that antialphas would form. The discovery, published in Nature, will inform the search for antimatter elsewhere, including on the International Space Station. On 29 April the space shuttle Endeavour will begin a journey to the station to drop off the Alpha Magnetic Spectrometer, which will look for primordial antimatter.

Space.com: The Pioneer anomaly, which caused deep space probes Pioneer 10 and 11 to slow down on their paths away from the sun may be solved. NASA first noted the anomaly 30 years ago. The broader scientific community began investigating it in 1998, and a host of reasons for the slow-down have been proposed, among them gravitational forces from the Kuiper belt, dark matter, or some other unidentified source; drag from the interplanetary medium; and radiation pressure, including thermal radiation from the heat of the probes themselves. Orfeu Bertolami, of the University of Porto in Portugal and colleagues created three-dimensional simulations of how thermal radiation emitted by the deep space probes bounces off their surfaces. They found that when the reflected heat was added into prior calculations of thermal effects, thermal radiation accounts for all of the anomaly, rather than the 66% previously supposed.

Nature: A piece of space debris as small as one centimeter long can cause serious damage to vital weather, communication, or missile-warning satellites, and the amount of debris orbiting Earth is increasing. The Space Surveillance Telescope, a ground-based telescope developed by the US Defense Advanced Research Projects Agency (DARPA), took its first images in February; after it passes an evaluation, it will be added to the US Space Surveillance Network.

The telescope’s 3.5-meter aperture and three-mirror system make it more powerful and faster than other ground-based telescopes in the network; it can collect data on dimmer objects more quickly and can scan the sky several times in one night. It will focus on the region about 35 000 km from Earth, where objects in geosynchronous orbit reside. The telescope will not be available for use in scientific experiments, but a subset of the data may be made available on a website operated by US Strategic Command, and researchers may be able to get further data on request.

National Geographic: All planets in our solar system with both a magnetic field and a significant atmosphere have auroras; on Earth, Jupiter, and Saturn they give off distinct radio emissions in addition to visual displays. Jonathan Nichols of the University of Leicester in the UK and colleagues say that radio telescopes are now becoming sensitive enough to detect radio signals from auroras of planets up to 150 light-years from Earth.

He and his team found that radio signal detection would be most useful for finding rapidly spinning, Jupiter-size planets that orbit stars shining brightly in ultraviolet UV wavelengths. According to Nichols, the best chance for detecting these planets lies with the Low Frequency Array (LOFAR)—which scans the night sky in low radio frequencies—due to its large collecting area and frequency range.

Various: Powerful electrical currents flow between Saturn and its sixth-largest moon, Enceladus. The Cassini spacecraft, since its arrival at Saturn in 2004, has passed the 500-km-wide moon 14 times and has gathered more data each time. Jets of gas and ice from Enceladus's south pole become electrically charged, forming an ionosphere. The motion of the moon and its ionosphere through the magnetic bubble that surrounds Saturn acts like a dynamo, which in turn creates the currents. Cassini's UV imaging spectrograph spotted a patch of UV light in Saturn's upper atmosphere near its north pole that indicated the presence of an electrical circuit; the Cassini Plasma Spectrometer's electron spectrometer (CAPS-ELS) detected the electron beams. The process observed between Saturn and its satellite may be a universal one; Jupiter and its moon Io have a similar electrical current between them that appears to develop through a comparable process.

Science: Pluto's atmosphere has expanded dramatically since 2000, when it extended about 135 km above the surface. It now extends more than 3000 km—nearly one-quarter the distance to Charon, its largest moon. The atmosphere's composition has changed as well; carbon monoxide has been detected in addition to the methane that was previously known to surround the orb. Because instruments in previous studies could have detected carbon monoxide, its appearance probably indicates a new stage in the seasonal development of Pluto's atmosphere. The unanticipated changes may be related to Pluto's recent close approach to the Sun or to long-term variations in the Sun's ultraviolet output. Because the dwarf planet was discovered a mere 80 years ago, we have yet to observe the entirety of its 248-year path around the Sun.

BBC: The massive solar flare of 15 February was caused by five rotating sunspots working in concert. Sunspots are centers of intense magnetic activity on the Sun's surface; solar flares occur when some of that magnetic energy is released over a period of minutes to tens of minutes. The sunspots involved in February's flare rotated through as much as 130 degrees as they developed, and they injected enough energy into the Sun's atmosphere to produce the largest flare seen in more than four years. The flare and its resultant coronal mass ejection (CME) caused no significant disruption to electronic communications or other infrastructure, despite their size. CMEs can cause disruption to satellites and telecommunications, but the alignment between Earth's magnetic field and that of the CME itself dampened the potential effects.

Science News: Recent cuts to NASA's budget mean that the European Space Agency (ESA) will have to scrap or scale down proposed space missions to study supermassive black holes and other high-energy phenomena. One of those missions, the Laser Interferometer Space Antenna (LISA), would have been the first dedicated space mission to search for gravitational waves—ripples in spacetime predicted by Einstein's theory of general relativity—generated by sources such as merging supermassive black holes. LISA was estimated to cost $2.4 billion; NASA's share would have been $1.5 billion. The other mission, the International X-ray Observatory, was originally going to use a large x-ray mirror to examine some of the universe's earliest supermassive black holes. The cost of that project was approximately $5 billion, with NASA's share being $3.1 billion. ESA is considering going forward with a revamped gravitational-wave mission, and smaller scale versions of other missions.

New York Times: Four winners were chosen from 22 proposals for NASA’s Commercial Crew Development (CCDev) 2 awards: Boeing received the largest award of $92.3 million; Sierra Nevada Corp, $80 million; Space Exploration Technologies Corp (SpaceX), $75 million; and Blue Origin, $22 million. The awards are designed to promote the development of commercially operated transport systems to ferry astronauts to and from the International Space Station. “We’re committed to safely transporting US astronauts on American-made spacecraft and ending the outsourcing of this work to foreign governments,” NASA administrator Charles Bolden said in a prepared statement. “These agreements are significant milestones in NASA’s plans to take advantage of American ingenuity to get to low-Earth orbit, so we can concentrate our resources on deep space exploration.”

Space.com: Astronomers in France have observed images of cosmic filaments, strings of gas in nearby clouds between stars in our galaxy, and believe that they may have been shaped by interstellar sonic booms. New photos from the European Space Agency’s Herschel Space Observatory have allowed astronomers to measure the widths of the filaments for the first time. They have found that no matter how long or dense the filament, its width is always about the same. Doris Arzoumanian, of the Laboratoire AIM Paris-Saclay, and colleagues have sought an explanation for this consistency. Comparing the observations with computer models, they have concluded that the filaments are probably formed when shockwaves—possibly caused by exploding stars—dissipate in the interstellar clouds, compressing and sweeping up gas found in the galaxy. "The connection between these filaments and star formation used to be unclear, but now thanks to Herschel, we can actually see stars forming like beads on strings in some of these filaments," said Göran Pilbratt, ESA Herschel project scientist.

Science: On 28 March NASA’s Swift spacecraft captured the biggest cosmic blast since the Big Bang. The blast is unusual in that instead of fading, which would indicate that a massive star had blown up, the high-energy radiation—actually a series of bursts—has continued to shoot out like a jet. The source of the explosion is at the center of a galaxy 3.8 billion light-years away. "We think that there is a dormant black hole there that has accreted a lump of matter—probably a star that has fallen into it," said astrophysicist Neil Gehrels, the lead scientist for Swift at NASA's Goddard Space Flight Center in Greenbelt, Maryland. If a star is "being torn up," he said, astronomers expect it to fade in the next few days. If it does not fade, they may need to revise their theory.

Space.com: The first person in space, Soviet cosmonaut Yuri Gagarin, made his flight 50 years ago on 12 April 1961. Now there is a new space race that is centering on space tourism, writes Clara Moskowitz for Space.com. Commercial companies are gearing up to send the first paying passengers to space on private spaceships. "It's an exciting time for the industry," said George Whitesides, president of suborbital spaceship company Virgin Galactic. "I really believe that we're at the edge of an extraordinary period of innovation which will radically change our world." The first flights will take passengers to an altitude of about 100 km, where they will experience about five minutes of weightlessness before returning to Earth. Although Virgin Galactic's SpaceShipTwo suborbital spaceplane is still being tested, regular tourist flights could start as early as 2012.

Science: Comets were once thought to be pristine repositories of the building blocks of our solar system. The most recent challenge to that belief comes from new analyses of the comet Wild 2. Planetary scientist Eve Berger of the University of Arizona and her colleagues have found several different sulfur-containing minerals in microscopic pieces of the comet, including a form of cubanite that is created only in liquid water below 210 °C. They conclude that the alteration most likely occurred when heat—from an impact or radioactive decay—melted pockets of ice within the comet, which then refroze. Primordial material left over from the formation of the solar system may still be out there, but scientists are having some difficulty finding it. That challenge only increases their desire to obtain a piece of comet to analyze.

Space.com: Yesterday researchers announced the discovery of a new mineral, Wassonite, found in a 4.5-billion-year-old meteorite discovered in Antarctica in 1969. "Wassonite is a mineral formed from only two elements, sulfur and titanium, yet it possesses a unique crystal structure that has not been previously observed in nature," NASA space scientist Keiko Nakamura-Messenger said in a statement. The mineral’s name honors John T. Wasson, a UCLA professor known for his achievements across a broad swath of meteorite and impact research. Meteorites may contain information about the formation of our solar system.

BBC: The University of Manchester’s Jodrell Bank Observatory in the UK will serve as headquarters for the world’s biggest and most sensitive telescope. The Square Kilometer Array will consist of thousands of small radio dishes spread over a distance of more than 3000 km. It is hoped that the €1.5 billion project, which involves partners from 20 countries, will reveal how planets and galaxies are born, give clues about the nature of dark energy, and help to detect signs of alien civilizations. Construction is scheduled to begin by 2016 and to be completed by 2024. The location of the telescope, which must be in the Southern Hemisphere, is yet to be decided, but could be built in Australia or southern Africa.

BBC: Mark Showalter of California's SETI Institute, Matthew Hedman of Cornell University, and their respective colleagues have come up with an explanation for why Jupiter’s and Saturn’s rings appear rippled. Showalter's team analyzed images of Jupiter's rings taken by the Galileo and New Horizons spacecraft. Hedman's team analyzed images of Saturn's rings taken by the Cassini spacecraft. Their analyses, published yesterday in Science, suggest that the ripples were caused by debris, most likely from a comet, tilting the ring relative to the planet's equatorial plane and then leaving a spiral pattern behind as it passed through. As time goes by, the ripples become more closely spaced, providing a means to deduce when the original impact occurred.

Daily Mail: Andrea Ghez, professor of physics and astronomy at the University of California, Los Angeles, has discovered a supermassive black hole at the center of one of the Milky Way's closest galactic neighbors. Using data from Chile's Very Large Telescope and NASA's Hubble Space Telescope, she and fellow astronomers studied the spiral galaxy NGC 253, which appears to host a twin of Sagittarius A*, the bright radio source that lies at the core of the Milky Way and harbors a massive black hole. Ghez's discoveries, along with the work of scientists studying other galaxies, have led astronomers to the surprising conclusion that most, if not all, of the universe's hundreds of billions of galaxies have supermassive black holes at their core. What's inside a black hole remains one of the biggest mysteries in physics, however.

Boston Globe: Yesterday NASA shut down its Stardust space probe, ending the craft's 12-year career. Launched in 1999, the probe was designed to study the asteroid 5535 Annefrank and collect samples from comet Wild 2. It completed its primary mission in 2006, when it returned a sample capsule of comet particles to Earth. The probe continued working and last month photographed a crater on an asteroid. "Like saying goodbye to a friend," said Allan Cheuvront, Stardust program manager for Lockheed Martin, who has worked on the probe since its design stage in 1996. "It's been an amazing spacecraft. It's done everything we asked; it's done it perfectly."

Christian Science Monitor: In this Q&A in the Christian Science Monitor, InnovationNewsDaily’s Stuart Fox interviews Ariel Waldman, who founded the website Spacehack.org. Per its home page, “Spacehack is a directory of ways to participate in space exploration, interact and connect with the space community, and encourage citizen science.” A self-professed space geek, Waldman helps laypeople get involved in promoting and conducting space science. She has advice on the merits of citizen science, the best space projects, and how to launch something into space for $150.

Nature: South Africa's commitment to hosting the world's most sensitive radiotelescope array is being tested by a request from oil giant Shell to drill for natural gas in the remote region that would house the facility, writes Linda Nordling for Nature. South Africa is competing with Australia to be the home of the Square Kilometer Array radiotelescope, an array of some 3000 antennas with a total collecting area of 1 km². Because Shell’s search for natural gas would run close to the proposed site for the SKA, it could cause problems. The big worry for the SKA is radio-frequency interference, says Adrian Tiplady, site-characterization manager at SKA South Africa. "The primary risk is electromagnetic interference generated from heavy industrial equipment, such as that associated with mining equipment, and any radio communication equipment associated with the mining activity," he says. "Seismic activity would also have an impact, but only within a closer proximity."

Space.com: Many skywatchers enjoyed the so-called supermoon over the weekend. As Tariq Malik reports for Space.com, viewers on Earth witnessed the largest full Moon in more than 18 years. The phenomenon occurred because the Moon was in its full phase and just 50 minutes past perigee—the point of its orbit that brings it closer to Earth. Saturday's full Moon appeared 14% larger and 30% brighter than the smallest full Moons Earth sees. Space.com has posted a beautiful collection of images submitted by readers.

BBC: The private archive of Fred Hoyle has been released to the public for the first time. Hoyle was an English astronomer and mathematician who is best remembered as a popularizer of science and as the man who coined the term "Big Bang." His papers, letters, and personal belongings are kept at St. John's College, Cambridge, UK. The collection, which took three years to catalog, is now available online.

Space.com: After a journey of more than six years and 5 billion miles, NASA’s MESSENGER spacecraft attained its goal of entering orbit around Mercury—the first spacecraft to do so. Launched in August 2004, MESSENGER has orbited the Sun 15 times and made one flyby of Earth, two of Venus, and three of Mercury. With seven science instruments, the spacecraft will study Mercury over the next 12 months, mapping its surface and studying its composition and atmosphere. Among other things, scientists hope to determine whether Mercury has any water ice and, on a larger scale, to gain insight into how the solar system formed and evolved.

Science: South Africa is competing with Australia for the proposed Square Kilometer Array radiotelescope, an array of hundreds of dishes spread over thousands of kilometers. Hence, South African astronomers are looking at converting old telecommunications dishes into radiotelescopes to produce a low-cost array that would span the continent, writes Daniel Clery for Science. Across Africa, the 30-meter satellite dishes that were once the backbone of the continent's communications are being replaced by fiber-optic cables. The astronomers have already developed political links with other African nations and hope to set up a couple of prototypes—perhaps in Ghana and South Africa itself—to encourage other governments to fund conversion of dishes within their boundaries.

Nature: Although it's possible to use a ground-based laser to move space debris out of the way of satellites, the idea hasn't been put into practice out of fear that the lasers could also be used as antisatellite weapons. To alleviate that fear, James Mason of NASA's Ames Research Center has proposed using a ground-based laser whose power is high enough to nudge debris out of the way but low enough to avoid harming spacecraft. Nature's Jon Cartwright reports that Mason's idea appears feasible—except, perhaps, for moving massive pieces. Its harmlessness is in doubt, however. Nudging a satellite off course could also constitute a hostile act.

CTV Edmonton: On Friday Jasper National Park was named the world’s largest dark-sky preserve by Canada’s environment minister Peter Kent. The 11 228 km² refuge, four hours west of Edmonton, in the Canadian Rockies, is 10 times the size of the next-largest designated area—Grasslands National Park in Saskatchewan. Dark-sky preserves are designated wilderness areas where strict lighting ordinances allow people to easily observe the night sky. Wilderness astronomy is a growing eco-tourism trend, where iPads and GPS-based star finders replace telescopes.

New Scientist: Earlier this week, a panel convened by the National Academy of Sciences issued its latest Planetary Science Decadal Survey, which lists in order of scientific priority the missions that NASA should undertake in the decade 2013–22. The top slot went to the Mars Astrobiology Explorer-Cacher (MAX-C), which seeks to land on the Martian surface and return to Earth with rock samples. The Jupiter Europa Orbiter (JEO), which would survey Jupiter's icy moon, came in second, followed by the Uranus Orbiter and Probe. Each of the top three missions is expected to cost several billion dollars. If NASA can't find the money, the panel recommends that some missions be delayed or replaced with cheaper ones.

Universe Today: High-energy particles called cosmic rays are constantly bombarding Earth from all directions, and have been thought to come from the blast waves of supernova remnants, writes Nancy Atkinson for Universe Today. But new observations from the PAMELA cosmic-ray detector show an unexpected difference in the momenta (per unit charge) of protons and helium nuclei, the most abundant components of cosmic rays. The difference is extremely small, but if they both come from the same kinds of accelerators, their spectra should be very similar. Oscar Adriani and his colleagues, who used data from the PAMELA instrument, say their new findings are a challenge to our current understanding of the acceleration and propagation of cosmic rays, which may be controlled by unknown and more complex processes. Their results were published in Science.

Space.com: Despite an increase in NASA’s Earth science budget for 2012, NASA was ordered by the White House to cut two large climate-change missions that were to launch by 2017. Eliminated were the Climate Absolute Radiance and Refractivity Observatory, and Deformation, Ecosystem Structure and Dynamics of Ice missions, according to Steve Volz, associate director for flight programs at NASA’s Earth Science Division. The other two top-tier Earth science missions—Soil Moisture Active and Passive and the Ice, Cloud, and Elevation Satellite-2—remain budgeted for launch in 2014 and 2016, respectively.

Guardian: A NASA astrobiologist claims to have found microscopic fossils of alien algae-like beings inside meteorites that landed on Earth. Writing in the Journal of Cosmology, Richard Hoover claims that the samples' lack of nitrogen, which is essential for life on Earth, indicates they are "the remains of extraterrestrial life forms that grew on the parent bodies of the meteorites when liquid water was present, long before the meteorites entered the Earth's atmosphere." Hoover, an expert on life in extreme environments who works at NASA's Marshall Space Flight Center, said that laboratory tests on the rocky filaments found no evidence to suggest they were remnants of Earth-based organisms that contaminated the meteorites after they landed. Rudy Schild, a scientist at the Harvard-Smithsonian Center for Astrophysics and editor of the journal, said: "The implications are that life is everywhere, and that life on Earth may have come from other planets."

Chronicle of Higher Education: To protect them from the harmful effects of cosmic rays, future astronauts may travel to Mars on asteroids. In a paper published in the March–April issue of the journal Acta Astronautica, Gregory Matloff, an adjunct associate professor of physics at the New York City Coll