NASA scientists don't often learn that their spacecraft is at risk of crashing into another satellite...
Three unusually long-lasting stellar explosions discovered by NASA's Swift satellite represent a new class of gamma-ray bursts that likely arise from dying stars hundreds of times larger than the sun.
The Vela pulsar traces out a loopy, hypnotic pattern reminiscent of art produced by a children's toy in this video created with data from NASA's Fermi Gamma-ray Space Telescope.