SUNSET: 
Mercury Shows Its True Colors
After six months of studying the innermost planet with NASA's Messenger spacecraft, planetary scientists are discovering unexpected surface compositions and are finally zeroing in on how the innermost planet came to be.
WISE's Survey of Near-Earth Asteroids
A heat-sensing NASA spacecraft finds that there aren't nearly as many large and midsize asteroids hovering near Earth as astronomers thought. Now we can all sleep a little easier.
One Image, Five Moons
A quintet of Saturn's moons come together in the Cassini orbiter's field of view for a group portrait.
GRAIL Heads for the Moon
By this time next year, the twin spacecraft of NASA's Gravity Recovery and Interior Laboratory mission should have given geophysicists an unprecedented peek at the lunar interior from crust to core.
Kenya's Rain of Meteorites
On the morning on July 16th, villagers heard a thunderous explosion in the sky and later found space rocks scattered throughout their corn fields.
The Moon's Uncertain Age
Is the lunar crust only 4.36 billion years old, as new results suggest, or at least 4.43 billion years old, as most researchers believe? The difference isn't much — but the implications for early lunar history are profound.
Opportunity Reaches Its New Home
The surviving one of NASA's two Mars Exploration Rovers is reaching the brink of a whole new adventure on Mars.
Juno Lifts Off for Jupiter
NASA's solar-powered spacecraft Juno successfully lifted off Cape Canaveral on Friday, August 5th.
Best Evidence Yet for Martian Water
NASA's Mars Reconnaissance Orbiter has found perplexing dark streaks that form seasonally and strongly suggest that liquid water flows on the Martian surface.
Big Splat Could Have Reshaped the Moon
Recent research suggests that the thick, heavily cratered crust on the Moon's far side could be the pasted-on remains of a second satellite that once orbited the early Earth.
Where No Spacecraft Has Gone Before
Dawn sends stunning images from Vesta of an uncharted alien world.
Earth's Traveling Companion
Astronomers have identified a small body sharing Earth's orbit in a gravitationally stable resonance that keeps it from hitting us or escaping. Finally, Earth has a Trojan asteroid to call its own.
A Closer Peek at Vesta
This week, Earth was hit by a barrage of intriguing images of Vesta — all courtesy of Dawn, NASA's latest asteroid orbiter!
Hubble Spots New Moon Orbiting Pluto
Astronomers using the Hubble Space Telescope have discovered a new moon orbiting the icy planet Pluto.
Does Air Pollution Alter Lunar Eclipses?
Observations of June 15th’s total lunar eclipse suggest that smoggy skies over China created unusual patterns in the umbral glow on the Moon.
Dawn Arrives at Vesta
NASA's spacecraft Dawn entered orbit around Vesta on July 16th and is preparing for a year's observation of the second-largest body in the asteroid belt.
More on Saturn's Thunderstorm
Two studies reveal that the white smear across Saturn's northern face was caused by a deep seated thunder storm that discharged powerful lightning bolts for days on end.
The Truth About Neptune's Spin
By tracking two visible features in Neptune's atmosphere, a University of Arizona astronomer has clocked a new spin rate for the blue planet. But does this mean the Voyager results from 1989 are wrong?
Asteroid Flyby Yields New Thinking
When the little asteroid 2011 MD zipped within 8,000 miles of Earth in late June, dynamicists realized they need to change the way they compute such close flybys.
Two More Moonlets for Jupiter
Astronomers have discovered a pair of tiny satellites traveling far from Jupiter. So which planet — Jupiter or Saturn — now has the most moons?
