Ars Technica: The European Space Agency is planning to crash a spacecraft into an asteroid. The Asteroid Impact and Deflection Assessment mission would actually comprise two spacecraft—one to crash, and the other to gather data. The first, called DART (Double Asteroid Redirection Test), would impact a near-Earth asteroid, 65803 Didymos, at a velocity of 6.25 km/s. The second, AIM (Asteroid Impact Monitor), would carry multiple sensors to observe the asteroid before, during, and after the impact. Such a study could aid research into asteroid deflection to prevent potential catastrophes caused by near-Earth objects striking the planet. Because DART’s velocity would be fast enough to vaporize pieces of the asteroid, the event could also provide the opportunity for researchers to study conditions that may have existed during the early solar system.
Science News: Microwave imaging traditionally uses a single, detector that is moved around to create a full image. By contrast, a new system, created by a team led by John Hunt of Duke University in North Carolina, uses a stationary detector and a thin strip of copper. The researchers created a specialized aperture by etching the copper with a pattern of spirals and loops, which turned it into a metamaterial. The patterning provides very precise control over what frequency of light passes through the aperture. By sending out microwaves of different frequencies, recording the waves that bounce back, and processing that data with a set of algorithms, the imaging system can build a very clear picture of the target with just one-fortieth of the data required by previous imagers. Hunt’s team has tested the technique only on very simple targets, but says that it should be effective in detecting any reflective metals, including wires and pipes in walls or concealed weapons. It could also be adapted for use in security systems to replace bulky video equipment.
New Scientist: Wind turbines work by spinning coils of copper wire through stationary magnetic fields. Two groups of researchers believe that by replacing the copper wire with superconducting wire, they can transform 2- and 3-MW wind turbines into 10-MW turbines. Among the other benefits, superconductors would reduce the weight, and because of the decreased resistance in the wires, they would also increase the power generation. However, some of the characteristics of superconductors make it difficult to maximize their effectiveness in turbines. For one thing, superconductors require very low temperatures to operate. To address that issue, the Suprapower consortium in Europe is using a new high-Tc superconductor that works at 20 K and therefore requires only one-seventh of the energy to cool as older superconductors. The researchers are still working to determine how to minimize warming from nearby systems. Another problem is the formation of magnetic vortices, which reduce the current flow, as the superconductors move through the magnetic field. To solve that problem, the US’s Advanced Research Projects Agency–Energy is funding a project led by Venkat Selvamanickam of the University of Houston, Texas. Both groups are still several years away from creating 10-MW turbines, but believe the projects could be applied to other areas of electrical generation and transmission.
Nature: To facilitate publication of scientific research, a new platform called the Episciences Project is scheduled to be launched this April. The brainchild of Jean-Pierre Demailly, a mathematician at the University of Grenoble in France, the project will consist of a series of free, open-access journals, whose articles will be culled from the arXiv preprint server. Each journal will have its own editor and editorial board, which will select the content and organize peer review of the articles. The Episciences platform will be maintained by the Center for Direct Scientific Communication, based in France. The project has the seal of approval of Tim Gowers, a Fields Medal winner and mathematician at the University of Cambridge who last year initiated a boycott of the world’s largest scientific journal publisher, Elsevier, in an effort to reform research publishing.