SUNSET: 
The Sun Really Rocks!
Newly released video shows that the entire Sun shimmies and shakes in the aftermath of a big solar flare.
"Pioneer Anomaly" Solved?
The first spacecraft to reach the outer solar system have been mysteriously slowing down for decades. Put aside the exotic explanations; it may be just a matter of heat.
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.
A Record-Breaking Gamma-Ray Burst
The visible-light glow of a gamma-ray burst briefly shone at magnitude 5.4, despite its distance of 7.5 billion light-years — more than halfway across the visible universe.
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.
A Rich Protoplanetary Soup
Infrared observations reveal a star with a protoplanetary disk infused with helpful organic compounds.
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?
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.
Ring Around a Saturn Moon?
During a close flyby of Saturn's largest icy moon in late 2005, several instruments aboard Cassini sensed (but didn't actually "see") what appears to be a trio of thin rings and a dust disk surrounding Rhea.
Four Martian Landslides Caught in the Act
A scarp along the edge of the Martian north polar cap is more active than anyone expected.
Ulysses Says Goodbye
After spending more than 17 years in space, a durable solar sentinel has lost its radio voice and its fuel lines will soon freeze solid.
See the Doomed Spy Satellite!
Until it reenters the atmosphere — whole or in pieces — in the days ahead, you can see the decaying satellite USA 193 with your own eyes. Here's how to find it.
Space-Station Astronomy
Solar telescopes are set to be installed on the International Space Station today. A trio of instruments will be added to the new Columbus module.
NASA Wants You!
The US space agency wants to give its soon-to-be-launched gamma-ray observatory a new name, and it has opened the floor for nominations. Do you have the perfect moniker for the next Great Observatory?
Mercury's "Better Half"
When it swept by the innermost planet on January 14th, NASA's Messenger spacecraft showed us a side of Mercury never before seen. After two weeks of intensive study, mission scientists have shared some of the flyby's intriguing results — including views of a "spidery" crater that has them stumped.
A Stardust-Free Comet
When NASA sent a spacecraft to grab samples of a comet and return them to Earth, scientists had high hopes that they'd finally be able to decipher how the solar system formed. Boy, were they wrong!
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.
