SUNSET: 
Mercury: The Incredible Shrinking Planet
During its first flyby of Mercury, NASA"s Messenger spacecraft found much less iron on the planet’s surface than expected and a cloud of ionized atoms — including water — caught up in the planet’s magnetosphere. And that’s just for starters.
SOHO Tallies Its 1500th Comet
The Solar and Heliospheric Observatory has now found more comets than all other comet discoverers put together — not bad for a spacecraft that was designed to study the Sun.
Ulysses' Space Odyssey Ends on July 1st
The only space mission ever to study the Sun’s poles directly will turn off at month’s end after a long life of trial and triumph.
GLAST Heads Up, Up, and Away!
NASA's newest space observatory is safely in orbit and getting ready to probe the high-energy universe.
Moonlets Perturb Saturn’s Ring
New observations from Cassini show small satellites are responsible for Saturn's F ring looking a little frazzled.
NASA UV Satellite Powers Down
After five years in orbit, CHIPSat enters a hibernation that may — or may not — be permanent.
"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.
GLAST Ready to Go
Next week, NASA will launch its latest space observatory to provide our best look at the most powerful beacons in the universe.
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.
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'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: 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.
Matter of Scale
Some ways to get your head around cosmic orders of magnitude.
Find a Missing Mars Lander!
Ever since it crash-landed in 1999, NASA's Mars Polar Lander has been playing "hide and seek" with scientists trying to locate its remains. Now they want you to try.
Hubble Servicing Delayed
NASA's upcoming service call on the Hubble Space Telescope won't happen till late September or early October.
Happy Birthday, Hubble!
Eighteen years ago today, astronauts aboard the Space Shuttle Discovery deployed the Hubble Space Telescope. And what an 18 years it's been!
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.
