SUNSET: 
TEST - Possible Galactic Supernova!
In February 2003, Sky & Telescope and the SuperNova Early Warning System (SNEWS) conducted a test of the AstroAlert system. Here's what it looked like.
Did a Comet Swarm Kill the Dinosaurs?
New evidence of another 65-million-year-old crater suggests the dinosaurs might have been killed by a 1-2 punch.
Our Stormy Sun
As one naked-eye sunspot group rotates off the disk, another swings into view to take its place. Both active regions continue to spawn flares and other energetic explosions.
A Recent Asteroid Crackup
Most asteroids are just pieces of their former selves. Now astronomers have traced back 39 of them to one collision.
Huge Ice Deposits Found on Mars
A NASA spacecraft has strong evidence that slabs of ice lie buried just below of huge portions of the Martian surface.
Leonid Meteors Roar In On Schedule
Skygazers worldwide got a treat Sunday as the Leonid meteor shower put on its best display in 35 years. This five-image composite by Kazuyuki Tanaka in Japan shows nine Leonids radiating from the Sickle of Leo (center). The Beehive Cluster is at the top. The best meteor shower in 35…
Will Leonids "Storm" for North America?
A 'meteor's-eye view' shows how Earth will be oriented for the first expected peak of the Leonid shower on November 18, 2001, at about 5 a.m. EST (2 a.m. PST). That's when dynamicists predict that Earth will encounter the most dense region of particles released by Comet Tempel-Tuttle. While the…