SUNSET: 
Earth-and-Sun Diamond Ring
Japan's Kaguya spacecraft, orbiting the Moon, captured this spectacular interplanetary vista as both the Sun and Earth rose over the lunar horizon on February 9th.
Moon's Puzzling, Thick-Skinned Far Side
Ours is a two-faced Moon. The familiar side is mottled with vast plains of ancient lava. But the unseen far side has a thick, rigid crust that doesn't give up its secrets easily.
Did the Moon Do a Face Flip?
We're taught that tidal locking of the Moon's spin and orbit has always kept its near side facing toward Earth. But a new study challenges that long-held notion.
Hayabusa Heads Home
Crippled by multiple system failures, a Japanese spacecraft continues its against-all-odds struggle to return to Earth after landing on an asteroid 3½ years ago.
Let's Google Mars
The world's most fascinating mapping utility now works on another planet.
The Curious Case of Martian Methane
Mars, it seems, is not quite dead. A team of observers has found methane in the Red Planet's atmosphere. This finding proves either that Mars has (or once had) life — or that the planet's interior occasionally burps.
Martian Mega-Rover Gets a "Time Out"
Plagued by a technical obstacles that could threaten its success, a $2 billion Mars rover has been postponed two years by NASA officials. The Mars Science Laboratory's new launch date is 2011.
A Very Oddball Comet
Periodic Comet Machholz 1 has such a unique composition that a researcher suggests it may have come from another solar system. Though the odds against this seem long.
Sleuthing Reveals Mars's Watery Past
New findings announced this week suggest that the Red Planet may have had an ancient ocean after all and that buried glaciers of ice have turned up in surprising places.
Chandrayaan 1 is a Hit
India's first deep-space mission has chalked up another success during the first days of its two-year mission: slamming an instrumented probe into the lunar surface.
Amazing Close-ups of Enceladus
Ever wonder what it'd be like to view the icy terrain of Saturn's enigmatically active moon as if you were just 12 miles above it? Now you can, thanks to Cassini's close brush with Enceladus on Halloween.
Mercury Gets a Second Look
When NASA's Messenger spacecraft flew past the innermost planet on October 6th, it mapped another 30% of the surface never before viewed by spacecraft and gave scientists tantalizing hints of what Mercury is all about.
Giant "Hurricanes" Ring Saturn's Poles
NASA scientists are scratching their heads over the monstrously large swirls revealed by the Cassini orbiter at the planet's top and bottom.
A Deep (Impact) Mystery
Deep Impact's in-your-face encounter with Comet Tempel 1 on July 4, 2005, created an enormous splash of dust and gas far more massive than anyone predicted. Some 3½ years later, planetary scientists are still struggling to understand what happened.
Kooky Kuiper-Belt Object
Observers have spotted a distant body that's veered far off the interplanetary highway.
Little Asteroid Makes a Big Splash
You'd think that a car-size space rock racing through space and slamming into Earth's atmosphere at night would put on a dazzling show. One did just that early Tuesday morning — but did anyone on the ground actually see it?
The New Face of Mercury
NASA's Messenger spacecraft slipped past the innermost planet on October 6th, revealing an amazing Mercurian landscape never before seen at close range.
The Sun Goes Round and (Less) Round
Incredibly precise measurements of the solar surface show that our star isn't quite as spherical as once thought.
The Solar Wind Takes a Breather
In the 50 years that space physicists have tracked it, the outward "wind" of charged particles coming off the Sun and flowing past Earth has never been weaker than it is right now.
Opportunity's Mad Dash
After spending 4½ years doing geologists' bidding on Mars, you'd think that NASA would give its rovers a rest. Instead, one of them has started rolling toward a large crater that it likely won't reach for two years.
