SUNSET: 
Messenger's Third "Taste" of Mercury
Today a NASA spacecraft zipped past the innermost planet at close range, a move designed to set up a return visit in 2011 that will cap seven years of wandering through the inner solar system. Three flybys down, one orbit insertion to go!
The Humid Moon
Just-released infrared maps of the Moon reveal traces of water and hydrated minerals (colored blue) clinging to large tracts of the lunar surface. Is there enough of it for future astronauts to collect and drink?
Planck Sees "First Light"
European astronomers are delighted that their new microwave-background spacecraft has successfully begun making its highly detailed map of tiny temperature variations across the sky — the key to revealing insights about how the Big Bang happened and how the earliest galaxies formed.
India's Chandrayaan 1 Goes Silent
Ground controllers abruptly lost contact with India's first lunar probe on August 29th, likely signaling the premature end of this promising mission.
Kepler Shows Its Promise
After just 1½ weeks of test observations, scientists are confident that the Kepler spacecraft is well on its way to discovering Earthlike planets around distant stars.
Martian Meteorite in 3-D
Rolling along over the sandy Meridiani Plain on Mars, the tireless rover Opportunity has chanced upon a hefty iron-nickel meteorite. Grab your 3-D glasses for an eye-popping closer look!
Spitzer Scope Warms to New Mission
Since exhausting its supply of ultracold liquid helium in May, the Spitzer Space Telescope has warmed to the point that two of its detectors no longer function. But NASA astronomers still have big plans for their orbiting eye on the infrared sky.
Hubble Readies for Full Operation
It took five grueling spacewalks by Space Shuttle astronauts and a billion-dollar investment to restore the Hubble Space Telescope to good health. Now NASA astronomers are nearly ready to show us just how good the 19-year-old space observatory is.
Apollo Landers Seen on the Moon
NASA's new Lunar Reconnaissance Orbiter has such a high-res camera that, at long last, it's possible to see the Apollo landers sitting on the Moon. You can even see the trails of astronauts' footprints! Browse the just-released pictures.
"First Light" for New Lunar Orbiter
It's just a calibration image, but this early view from NASA's Lunar Reconnaissance Orbiter shows off the stunning potential of its mapping cameras.
U.S. Lunar Probes Go Loopy
Two NASA spacecraft, launched last week, have successfully swung past the Moon. One is getting ready to study it; the other is a few months away from crashing into it.
A "Briny Deep" Inside Enceladus?
Planetary scientists are crazy about Saturn's most active moon but can't agree on what powers the towering plumes gas and particles erupting from near its south pole. New findings, published this week, hint that the water vapor might be slowly evaporating from a salt-laced ocean in deeply buried caverns.
NASA Returns to the Moon
Two U.S. spacecraft are on their way to survey the Moon as never before — and to settle the debate over whether water lies frozen at the lunar poles.
Kaguya Mission Ends with a Flash
After circling the Moon for two years, the Japanese spacecraft Kaguya slammed into the lunar surface on June 10th — an event captured by an observatory in Australia.
Whirlpool Awash with Hints and Promise
A picture perfect Whirlpool galaxy bodes well for the scientific promise of the newly launched Herschel Space Telescope.
Exoplanet Mapping Tested on Earth
Researchers are developing a method to detect oceans and clouds on planets orbiting other stars. To test this idea, they aimed the telescope aboard NASA’s Deep Impact probe toward Earth, and made a rough map of our world.
Planck and Herschel to Probe Inflation and Starbirth
The Herschel Space Observatory and the Planck Surveyor, launched May 14th on a single Ariane 5 rocket, will peer deeply into dust clouds and map the microwave background.
Auroras from "Space Tornadoes"
Another confusing piece of the puzzle has been added to the picture of how the Northern Lights work.
Hubble Telescope's 19th Birthday
The greatest of NASA's Great Observatories rocketed into space 19 years ago. After a rocky start, it fulfilled its promise as Astronomy's Discovery Machine.
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!
