SUNSET: 
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.
The Darkest Exoplanet Yet
Think you know all the kinds of alien worlds? Think again. Two astronomers have just added another weirdo to the list: an exoplanet darker than powdered charcoal.
Hunt for Supernova Origins
New observations are beginning to uncover the origins of some Type Ia supernovae.
Galaxies Make Giant Gas Clouds Glow
The Lyman-alpha blobs have been a mystery since their discovery in 2000. Recent research however might offer clues.
Perseids: Looking Up, Looking Down
Earthbound observers struggled to see August's famous "shooting stars" through a sky awash with moonlight. But a shutterbug astronaut aboard the International Space Station had the best view of all!
Battle of Marathon's 2,500th Anniversary
There is a special significance to the late-summer full Moons of 2011 — this season marks the 2500th anniversary of the Battle of Marathon.
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.
The Return of Cosmos
The most successful PBS television show ever — now 30 years out of date — is being reborn as a new series to be aired in 2013.
Off Year for the Perseid Meteor Shower
The year's best-known display of shooting stars is usually dramatic and dependable. But even though light from a full Moon will wash out the fainter arrivals when the shower peaks early in the morning of August 13th, you'll still see the shower's brightest meteors streak across the sky.
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.
Great Sun This Week
This week the Sun is putting on its best show in nearly a decade.
Amateur Search for White-Dwarf Planets
Arizona amateur Bruce Gary is assembling a pro-am team to look for planets orbiting dead stars.
Where No Spacecraft Has Gone Before
Dawn sends stunning images from Vesta of an uncharted alien world.
Tour August's Sky! | July 29th, 2011
This is your last chance to spot Saturn before it sinks into the evening twilight. But there are many other celestial attractions to look for on August evenings.
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.
Kepler's Dilemma: Not Enough Time
NASA's planet-hunter has already identified more than 1,200 exoplanet candidates. But project managers now quietly acknowledge that the spacecraft will have serious difficulty spotting habitable, Earth-size worlds by the mission's end next year.
Amateur Discovers A Planetary Nebula
Austrian amateur Matthias Kronberger has found a planetary nebula near the northern constellation of Cygnus, the Swan. His discovery might help scientists understand the role of stellar companions in the formation of these glowing gas clouds.
From Stars to Stardust
Astronomers have determined that a recent supernova in the Large Magellanic Cloud created a half-Sun's worth of dust — hinting that such stellar explosions might be an unexpectedly rich source of dust throughout the universe.
