SUNSET: 
What a Difference a Decade Makes
It's been a decade since Mars Pathfinder touched the surface of Mars and heralded a new era of Martian exploration.
Ceres: The Wet Look
Mounting evidence suggests that the largest asteroid is hiding a large cache of water ice beneath its surface.
Is there another planet besides Earth whose moon(s) would fit perfectly over the Sun?
It is amazing when you think about the coincidence of the Sun being 400 times bigger than our Moon, yet 400 times farther away, producing an almost perfect fit for a total solar eclipse. Is there another planet whose moon(s) would fit perfectly over the Sun, or are we just…
What was the cloud spotted near the western horizon August 31, 2004?
Around 9 p.m. on August 31, 2004, I saw a bright patch of light about half the size of the Moon near the western horizon. It moved slowly upward and fluctuated somewhat in brightness. Through an 8-inch Schmidt-Cassegrain telescope here in New Bloomfield, Pennsylvania, there were two points of light…
Call for Observations: Saturn's Moons
Advanced amateurs with CCD-equipped telescopes are encouraged to measure the "opposition effect" — a brightening expected to occur in the Saturnian system during this upcoming opposition (January 13–14).
A New Comet Machholz
Found lurking among the dim stars of the constellation Eridanus, Don Machholz's 10th cometary find will brighten steadily in the months ahead.
A Comet's Brush with the Sun
The SOHO spacecraft watched as a comet swung past the Sun.
Moon Study Tracks Changes in Earth's Cloud Cover
Scientists are looking to the Moon to learn about Earth's climate change.
Cassini Calls on Phoebe
Cassini's first rendezvous with a Saturnian moon was a date to remember.
Storm Watch on Mars
If events of the past 30 years are an indication, there's a good chance that the Martian landscape may soon be cloaked by a major dust storm.
Another Martian Dust Storm
Less than one month after a localized dust storm appeared on the Martian surface, another dust cloud has spring up.
Uranus, Neptune, and Pluto in 2003
With our detailed charts, you'll be able to locate the outer planets Uranus, Neptune, and Pluto the rest of the year.
All Eyes on Pluto
July's encounters with two 12th-magnitude stars could rewrite the textbooks on the Pluto-Charon system.
Martian Flare Watch
Sharp-eyed amateurs have an opportunity to observe a rare phenomenon on another planet and help solve a long-standing puzzle.