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.