Oct 3 2005
From The Space Library
Lesa B. Roe replaced the retiring Roy D. Bridges Jr. as Director of NASA's LaRC. Roe, who had begun working with NASA in 1987, had served as LaRC's Deputy Director since June 2004. Before that, she had been LaRC's Associate Director for Business Management since August 2003. Bridges had served as Director of LaRC from June 2003 until his retirement from NASA. (NASA, “Langley Center Director Lesa B. Roe,” 3 October 2005, http://www.nasa.gov/centers/langley/about/roe_bio.html (accessed 13 July 2009); NASA, “Gen. Roy D. Bridges Named Langley Center Director,” news release 03-042, 13 June 2003.)
Astronomers announced that they had discovered the source of short gamma-ray bursts (GRBs), which had been an enigma for decades. Gamma rays are the most energetic and deadly form of electromagnetic radiation. Although scientists had already discovered that supernovas cause long GRBs, which last for approximately 2 seconds, they had remained uncertain of the causes of short GRBs, which last less than 1 second. Using data from numerous NASA satellites, 130 astronomers from around the world found that short GRBs originate from neutron stars and not~as some theories had suggested~from supernovas. More specifically, satellite data showed that short GRBs originate from collisions involving a neutron star and either another neutron star or a black hole. However, the data was not conclusive regarding the exact type of collision that causes short GRBs, because the brevity of these events makes them difficult to observe directly. (Luigi Pir, “Short-Burst Sources,” Nature (London) 437, no. 7060 (6 October 2005): 822-823; Dennis Overbye, “Scientists Trace Gamma Rays to Collision of Dead Stars,” New York Times, 6 October 2005.)
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