SUNSET: 
Moonlets Perturb Saturn’s Ring
New observations from Cassini show small satellites are responsible for Saturn's F ring looking a little frazzled.
"Holy Cow!" — Phoenix Spots Ice
If the Phoenix lander hadn't been able to find ice on Mars within reach of its robotic arm, NASA scientists would have been majorly bummed. They needn't have worried.
Is Mars Too Salty for Life?
A just-published study, coincidentally appearing as Phoenix prepares to get the dirt on Martian habitability, argues that the Red Planet's soil is at least 10 to 100 times saltier than Earth's oceans.
Amateur Finds Fastest-Spinning Asteroid
While chasing near-Earth asteroid 2008 HJ with a remotely controlled telescope in Australia, Richard Miles made a record-setting discovery.
Jupiter Sports a Third Red Spot
Jupiter's new spot may herald global climate change for the gas giant.
Phoenix's Amazing Photo Finish
Whether by precise planning, good luck, or both, a high-power camera aboard the Mars Reconnaissance Orbiter captured the Phoenix lander during its parachute descent with a menacing crater looming in the background.
Phoenix Readies for Arctic Adventure
So far, so good. NASA's Phoenix spacecraft has reached the north-polar plains of Mars, and scientists on Earth are getting ready to put it to work.
Phoenix: Redemption at Mars
NASA's Phoenix spacecraft has dropped gently onto the north-polar plain of Mars — easing painful memories of a similar craft lost 8 years ago and rewarding its anxious handlers with stunning views of the surrounding landscape.
Mars Rover Unearths Ancient Hot Springs
The Mars rover Spirit uncovers evidence for hydrothermal activity on the Red Planet and a possible cache for microbial fossils.
The Sun Really Rocks!
Newly released video shows that the entire Sun shimmies and shakes in the aftermath of a big solar flare.
Apophis ad Absurdum
Was it a simple misunderstanding, sensationalist reporting, or an outright hoax? Whatever the answer, a recent story about a German student embarrassing NASA's asteroid experts shows how little mass-media reporters know about basic science — and how unlikely they are to check the facts.
Phobos Gets a Close-up
The small army of spacecraft now operating on and around Mars don't spend all their time watching the Red Planet. Check out this just-released view of one of Mars's moons.
What's Inside Enceladus?
In a daring dash over the south pole of Enceladus, the Cassini orbiter found organic molecules gushing from icy fractures on the Saturnian moon's surface — and hints that a reservoir of liquid water might exist deeper down.
Titan's Free-Floating Crust
Saturn's giant moon isn't spinning the way a well-behaved satellite should — and some scientists argue that this deviant behavior is due to a global ocean hidden beneath its icy crust.
Comet Hale-Bopp Still Lives
It's nearly as far away as Neptune, but the frozen gas in the Great Comet of 1997 is still melting.
Cassini Gets a Face Full of Water
Who would have guessed that a decade after Cassini headed to Saturn, mission scientists would be flying it through an ice volcano's plume?
A Whiff of Water From the Moon
After studying the samples returned by Apollo astronauts, geochemists concluded that Moon is probably the driest place in the solar system. But a new study has turned up a tiny trace of water in some green-colored volcanic beads collected near Mare Imbrium.
What Happened to Mars?
Something happened to the Red Planet early in its history that left roughly half of it heavily cratered and the other half smooth and flat. Was this global facelift the work of a giant impact?
Genesis Finding: Earth Has a Problem
Even as the Genesis spacecraft lay in a crumpled heap on the ground after its reentry chute malfunctioned in September 2004, its scientists remained confident that they would salvage the mission and answer fundamental questions about how the solar system formed. Now they have — and the results have already sent cosmochemists back to the drawing board.
Getting To Know Mercury
Planetary scientists have gathered in Houston, Texas, to get the latest news on what NASA's Messenger spacecraft learned when it zipped past the innermost planet two months ago.
