SUNSET: 
Why Are We Moving Away from the Sun?
A few years ago astronomers became aware that the Sun-Earth distance, the astronomical unit, is gradually growing larger. Now a team of Japanese theorists have looked to the tides for an explanation.
Auroras from "Space Tornadoes"
Another confusing piece of the puzzle has been added to the picture of how the Northern Lights work.
What's Going on Inside Enceladus?
One of Saturn's icy moons has a tummy ache, causing it to spew jets of gas and icy particles hundreds of miles into space. Researchers aren't sure of the cause — but they have some interesting guesses!
Craters Reveal Ice in the Martian Dust
High-resolution images from orbit reveal tiny craters — created within the past year — surrounded by splashes of water ice dredged up from just below the Martian surface.
Meteorites Found from Asteroid 2008 TC3
Last December a determined U.S. researcher traveled to Sudan to recover pieces of an asteroid that slammed into Earth's atmosphere only 19 hours after being spotted. It was a long shot that paid off beyond his wildest dreams.
Sculpting the Asteroid Belt
New simulations show that when the giant planets shifted their orbits 4 billion years ago, the asteroid belt became a wild and crazy place.
From Venus to Gaia… and back down to Earth
One of the many big differences between Earth and Venus that could have a bearing on habitability is the absence of a strong magnetic field on Venus. So is it just dumb luck that we have a magnetic field and Venus doesn’t? Or is something deeper going on here?
Saturn's Newest Moon is a Ringer
A tiny moonlet discovered around Saturn is the likely source of the planet's G ring.
Space Rock 2009 DD45 Buzzes Earth
Roughly 100 feet across, the tiny asteroid designated 2009 DD45 is about to get its 15 minutes of fame.
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.
