BBC: At the 221st American Astronomical Society meeting, Christopher Burke of the Seti Institute announced that the number of planet candidates the Kepler space telescope had identified had reached 2740. Since 2009 Kepler has observed more than 150 000 stars in the same area of space. François Fressin of the Harvard–Smithsonian Center for Astrophysics and his colleagues have been examining the stars for minute dips in brightness that may be caused when a planet passes in front of one. By ruling out other possibilities, and by calculating the masses of the planets, Fressin’s team has determined that 17% of the stars have planets up to 1.25 times the size of Earth that have orbits of less than 85 days. That means that there may be more than 17 billion Earth-sized planets in the Milky Way.
Los Angeles Times: Launched last year, the Nuclear Spectroscopic Telescope Array (NuSTAR) images the sky in hard x rays. The high-resolution images at energies up to 79 KeV are more than 100 times better than what was previously available, according to Fiona Harrison of Caltech, who is leading the NuSTAR research. The telescope has been focusing on two unusual black holes in a galaxy 7 million light-years away and on Cassiopeia A, a supernova just 11 000 light-years away. Harrison hopes that the higher resolution will help to explain why the two black holes are 10 times brighter than most and why particles from Cassiopeia A have been accelerated to such high speeds. The use of x rays provides information that other wavelengths of light cannot. High-energy x rays are able to pass through the clouds of gas and dust that obscure visible and IR light.
Nature: A study of lake sediments near mining operations in Canada has shown increased levels of polycyclic aromatic hydrocarbons (PAHs), a family of organic pollutants that includes several carginogens. In a paper published in the Proceedings of the National Academy of Sciences, Joshua Kurek of Queen’s University in Kingston, Ontario, and colleagues found that the higher levels of PAHs coincide with oil sands development in the province of Alberta. Extraction of crude oil from the sands began almost a half century ago, but has ramped up significantly since the 1990s, and the environment may be suffering. “The signature of the PAHs and the timing strongly suggest that development and the refining of the oil sands plays a role in PAHs increasing in these lakes,” said Kurek. Because production is expected to double between 2011 and 2020, Alberta’s government plans to create an independent agency to monitor the situation.
New York Times: Although the Fukushima Daiichi nuclear disaster occurred more than a year and a half ago, cleanup of the contaminated environment has been slowly and shoddily executed, reports Hiroko Tabuchi for the New York Times. Rather than take advantage of local and international expertise in decontamination methods, Japan’s government has turned much of the effort over to the country’s largest construction companies, which have little radiological cleanup expertise. And to save money, the companies have been using primitive, potentially hazardous techniques. At one elementary school about 12 miles from the Fukushima nuclear plant, “construction workers blast buildings with water, cut grass and shovel dirt and foliage into big black plastic bags—which, with nowhere to go, dot [the] landscape like funeral mounds,” writes Tabuchi.