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.
Martian Dirt is Friendly to Life
The Phoenix lander's first wet chemical analysis of the Martian surface confirms water’s thumbprint and finds the kinds of inorganic minerals you'd have in a backyard garden.
The Two Faces of Mars
Just about the time a Mars-size body creamed Earth with enough force to create the Moon, another big planetoid might have slammed into Mars itself. The result? A two-faced planet and the solar system's largest impact crater.
The Mystery of Saturn’s Double Aurorae
New infrared observations reveal a second auroral ring on Saturn that may help astronomers understand what causes the planet's aurorae in the first place.
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.
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 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.
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.