Gamma Ray Bursts Could Have Led to Extinctions
Gamma ray busts are the most powerful known explosions in the Universe, so if one went off in our galactic…
Dark Matter at the Heart of Galaxy Groups
When you look at a galaxy, you can only see a fraction of its total mass. The rest is made…
Discovery Reaches the Launch Pad
In preparation for its return to flight, the space shuttle Discovery made the long slow journey atop its Crawler Transporter…
Early Galaxy Growth Spurt Spotted
The Chandra X-Ray Observatory has detected distant galaxies going through a period of tremendous star formation, at the same time…
Rovers’ Contracts Extended a Third Time
NASA has given Spirit and Opportunity up to another 18 months to continue rolling around the surface of Mars in…
Sedna Probably Doesn’t Have a Moon
When the planetoid Sedna was discovered last year, astronomers noticed that it had a very slow rotation speed, only turning…
Cassini Completes Fourth Titan Flyby
NASA's Cassini spacecraft made another close pass of Titan, Saturn's largest moon, on March 31, delivering new images and data…
Light Seen From Earliest Stars
Astronomers have used the Spitzer and Hubble space telescopes to see some of the first stars that formed in the…
Swift Measures the Distance to Two Blasts
Since its launch late last year, NASA's Swift space telescope has already spotted 24 gamma-ray bursts - the most powerful…
Searching for Gravity Waves
When he developed his General Theory of Relativity, Einstein predicted that the motion of large masses should create ripples in…