SUNSET: 
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.
Haumea: Dwarf-Planet Name Game
After three years of controversy over who discovered it, a large object in the Kuiper Belt has finally been christened by the International Astronomical Union — but the discovery rights are far from settled!
Rosetta's "Jewel in the Sky"
European scientists are excitedly poring over results from the Rosetta spacecraft's close flyby of asteroid Steins, even though an unexpected camera glitch cost them the best views of its cratered surface.
Phoenix Surpasses 90-day Milestone
NASA's newest lander has now been scratching, digging, sniffing, baking and tasting samples of Martian polar terrain for more than three months. How long can it survive in the fast-approaching winter — and how much more can it learn?
Perseids Hitting the Moon
Amateurs have helped lead the way in recording the flashes of meteoroids hitting the Moon's night side.
The Great Planet Debate
A controversial vote to define "planet" two years ago created more confusion than clarity. So scientists, educators, and curious hangers-on have gathered to get a better handle on what to call the menagerie of worlds that inhabit our solar system and those of other stars.
New Enceladus Closeups Now Arriving
The Cassini spacecraft is returning the data from Monday's close flyby of icy Enceladus, and NASA is putting up the first raw images.
Our "Goldilocks" Solar System
Think our planetary family is normal? Think again. It turns out that the Sun and its retinue formed when the interstellar mix was just right — not too much gas, not too little, and stirred gently for just the right amount of time.
Titan Makes a Splash
It's not covered by a global ocean, as theorists once thought. But Saturn's big moon does sport pools of liquid ethane big enough to float anyone's boat.
An Electrifying Whodunit
Thanks to a quintet of identical spacecraft, space physicists have settled a decades-old debate over what triggers violent electromagnetic substorms inside Earth's magnetosphere.
Earth and Moon Dance for a Far Camera
From more than 30 million miles away, a NASA spacecraft snapped away as the Moon made a graceful pass in front of Earth's colorful disk.
Make Way for Makemake
It took three years to settle on a name for the third-largest object in the Kuiper Belt.
Mars's Ancient Water Works
New observations from a NASA orbiter reveal that water and rock freely mingled across (or under) much of the Red Planet's surface.
Asteroids with Split Personalities
Where did the dozens of known binary asteroids come from? According to a new finding, sunlight alone can force a body to spin in such a frenzy that it literally flies apart.
