Science Current events

Summary-

Scientist at NASA, using the US space agency's Fermi telescope, detected a massive gamma-ray explosion in space. This explosion contained energy ranging from 3,000 to 5 billion times the amount of energy in visible light! Most visible light contains about two to three electron volts, but these explosions had into the million and billions of electron volts. This enormous blast was determined to have occurred about 12.2 billion light-years away. To put it into perspective, the sun is only eight light-minutes away, and Pluto is twelve light-hours. A star has a lifetime, and when it dies, it explodes after its lifetime is up, which is called a supernova. This explosion was equivalent to 9,000 supernovae! Gamma-ray burst happen when stars run out of nuclear fuel and collapse. These can be either long bursts, which last more than two seconds and happen in large stars, or short bursts, which last less than two seconds and happen in small stars. In short gamma-ray bursts, stars simply explode and form supernovae. In long bursts, the core collapses and creates a black hole into which other stars fall. Studying gamma-ray bursts allows scientists to "sample an individual star at a distance where we can't even see a galaxy clearly” says the astrophysicists at NASA.

Work Cited-
http://news.yahoo.com/s/afp/20090219/sc_afp/sciencespaceastronomy