One of the European Space Agency 's (ESA) greatest gifts marks its fifth year in space. Launched February 28, 2002, from Kourou, French Guiana, Envisat is the largest and most complex environmental satellite. The spacecraft has gathered more than 500 terabytes worth of images of our home planet. As we witness New Horizons' milestone of reaching Jupiter, consider that Envisat has traveled nearly the equivalent of a jovian roundtrip. The 10...

This image made by the Chandra X-ray Observatory in 2004 shows SN 1572, the youngest supernova remnant in the Milky Way. It is sometimes referred to as “Tycho’s nova,” after the 16th century astronomer who observed and wrote about it. NASA/CXC/MIT/ UMass Amherst/M.D.Stage et al. A lot of stars came out last week for the Oscars, but astronomers were more interested in the two novae , or "new stars," discovered by Japanese...

I'm not a slouch when it comes to observing. In fact, I'd go so far as to say I'm a pretty good observer. I've recorded a lot of "firsts" and "bests" during my random walk through the sky. I've also observed with some of the world's best observers. Many names advanced amateur astronomers would recognize instantly. Some they would not. Well, add another well-recognized name to my life-list: Dave Eicher. Sound...

Supernova 1987A shines brightly near the center of this photo, taken March 2, 1987. The wispy gas clouds of the Tarantula Nebula lie to the supernova’s left. Marcelo Bass/CTIO/NOAO/AURA/NSF It was 20 years ago today, A shock wave started 87A, Its behavior was pretty wild, Left a core of a dozen miles, So let me introduce to you, A star that launched a million cheers, Supernova 87A. (Lennon-McCartney-Talcott [with apologies to the first two]...

What do an asteroid and a tsunami have in common? Plenty, it turns out. It seems one of the toughest issues for politicians to address in a timely way is a natural hazard with potentially catastrophic consequences but whose risk of actually occurring is highly uncertain. For a moment, think about the tsunami that left about 230,000 people dead or missing around the Indian Ocean basin. Scientists there and abroad were aware of the tsunami risk. Even...

The Sun shone brightly on the snowy slopes of Aspen during this week’s supernova workshop. But the participants, including your humble correspondent, were more interested in exploding stars. Larry Marschall With 12 inches of fresh powder on the slopes at Aspen, you might think everyone at this week's supernova workshop would be grabbing their skis or snowboards, donning their parkas, and heading off to one of the town's four mountains...

NASA/Philip Stooke Three cheers for University of Western Ontario geologist Philip Stooke, who deserves the Photoshop Wizard of the Year award for his painstaking restoration of panoramic images shot by the Lunar Surveyors in the 1960s. In his spare time, between teaching cartography and planetary science, Stooke transformed crude and obscured pans of the lunar surface into crisp, modern-looking images. He did it manually, using the standard image...

I've created a gallery featuring some pictures of the Winter Star Party — a sold-out event held February 12–18 at Big Pine Key, Florida. Click here to view these images.

Walker Books Today marks the 534th birthday of Nicholas Copernicus, the Polish astronomer who published the first modern heliocentric theory, in the 16th century. Although this should be Copernicus' special day - after all, it's not every day a guy has enough candles on a birthday cake to do more damage than Mrs. O'Leary's cow - let's recognize the person who convinced Copernicus to publish his theory, De revolutionibus . Having...

Astrophotographer Jack Newton was one of Arizona Sky Village’s first inhabitants. His attached observatory houses a 16-inch Meade Schmidt-Cassegrain telescope. Newton routinely photographs the Sun and searches for supernovae. Michael E. Bakich In an era when really dark skies are increasingly hard to find, a group of diehard observers has set up a retreat catering to the fondest wishes of amateur astronomers. In the deep southern part of Arizona...