SUNSET: 
A Bird's-Eye View of the Sun
What's it like to coast high over our star? The European-built spacecraft Ulysses is doing that right now — for its third and likely final time.
Reunion with Mercury
For the first time in nearly 33 years, mission controllers have guided a spacecraft past Mercury, a fire-and-ice world that may hold many keys to the solar system's formation.
Mars Dodges a Bullet
Fortified with two months of telescopic tracking, dynamicists say there's now virtually no chance that a small asteroid will strike Mars later this month.
Cassini's Popularity Contest
After a month-long contest, the Cassini Imaging Central Laboratory for Operations (CICLOPS) has announced which images of Saturn are fan favorites.
Your Audio Sky Tour: January 2008
Here's an introduction to the wonders of January evening sky — the impressive Quadrantid meteors, the gleaming planet Mars, and the glittering stars of Orion and Taurus. Host: S&T's Kelly Beatty. (5MB MP3 download: running time: 5m55s)
Odds of Mars Strike Now 1-in-25
Astronomers have been watching a small asteroid that, they now say, has a 4% chance of colliding with Mars on January 30th.
Mars in the Crosshairs?
Astronomers are waiting to see what becomes of a skyscraper-size asteroid that has a 1-in-75 chance of hitting Mars in late January.
Tunguska's Blast: Less is More
Aided by high-def supercomputer simulations, two researchers now argue that small asteroids striking Earth — like what happened over Siberia in 1908 — may pose greater danger than previously believed.
Earth's Magnetosphere: On the Ropes
A constellation of five identical orbiting probes has detected skirmishes with the solar wind along Earth's magnetospheric front lines.
Deep Impact's New Assignments
Put to sleep after its smash success in 2005, one of NASA's interplanetary craft is getting a chance to search for extrasolar Earths and to visit a second comet.
Thirty Meter Telescope Moves Ahead
Thanks to a just-announced commitment of $300 million, astronomers and engineers can get ready to build the Thirty Meter Telescope — far larger than any other telescope on Earth.
Saturn's Sci-Fi Moons
Just when you thought you'd seen everything the ringed planet has to offer, the Cassini orbiter glimpses bizarre little moons shaped like flying saucers.
My Kind of Beauty Contest!
What's the most beautiful image taken by the Cassini spacecraft since it arrived at Saturn? Vote for your favorite today!
Lightning on Venus
The world next door seemed hellish enough with an atmosphere 90 times the sea-level pressure on Earth and surface temperature of 900°. Now, scientists say, there's lots of lightning — and what little water it has seems to be escaping to space.
Your Audio Sky Tour: December 2007
Download this podcast to guide you to the wonders of December's evening sky — like Orion leaping up over the eastern horizon with gleaming Mars by his side. Host: S&T's Kelly Beatty. (7MB MP3 download: running time: 7m20s)
Earth at Night: Not a Pretty Sight
Rosetta's nighttime snapshots of the Eastern Hemisphere show that the fight against light pollution has a long way to go.
Will the UK Bail on Gemini?
Budget woes are forcing the United Kingdom to abandon its share of one of the world's premier observatories.
What Happened to Comet Holmes?
Despite scrutiny by an army of professional and amateur observatories — even the Hubble and Spitzer space telescopes — we may never learn what made a nondescript comet blow its top in late October.
Our Sun's Twin
A faint but observable star in Draco is the closest match yet to the one at the center of our solar system.
Rosetta Attacks!
Briefly mistaken for an asteroid headed toward Earth, a European-built comet chaser zips by en route to its deep-space rendezvous.
