SUNSET: 
A Great Time for Space-Station Watching
For the next week, the enormous International Space Station will be slam-dunk easy to spot in the evening sky — if you know where and when to look for it.
So-So Prospects for Comet Elenin
Discovered in December, an inbound comet will reach perihelion in September and likely be a nice sight in binoculars — but barely visible, if at all, to the unaided eye.
Kepler's Bonus: New Insights on Stars
Using observations from NASA's Kepler spacecraft, astronomers have found that about one-fourth of stars like the Sun slowly throb in ways that reveal their sizes and masses as never before.
The "Pioneer Anomaly": Case Closed
A mysterious force has been slowing down the starbound Pioneer 10 and 11 probes for decades. A fresh analysis confirms the suspicion that it was nothing more than heat reflecting off each probe's big communication dish.
S&T's Audio Sky Tour for April 2011
Look out! Jupiter is no longer ruling the evening sky, and sky critters are on the march in the north, east, and south.
Tour April's Sky! | March 31st, 2011
Look out! Jupiter is no longer ruling the evening sky, and sky critters are on the march in the north, east, and south.
Messenger Gets to Work
With about 30 orbits of Mercury under its belt and another 700 to go, a NASA spacecraft is starting to reveal the innermost planet's true identity.
An Amazing Aurora Video
Night after freezing night, Norwegian photographer Ole Salomonsen gathered aurora photos — 50,000 in all — to produce a breathtaking video that reveals the northern lights' true splendor.
New Insights on Lunar Swirls
Comet impacts? Magnetic oddities? Crashed alien spaceships? Soon scientists hope to solve the longstanding mystery of bright swirls like Reiner Gamma on the lunar surface.
Messenger: Mercury's New Moon
The fleet-footed planet of the ancients has a new companion — a NASA spacecraft that will now call it home after a convoluted, 6½-year-long, 5-billion-mile interplanetary cruise.
Is Water Flowing on Mars?
Spacecraft images are keeping an eye on little surface flows on Mars that show up in midsummer, then fade over time. It's the strongest suggestion yet that the Red Planet can get wet.
Remembering James Elliot, 1943–2011
The co-discoverer of Uranus's rings and Pluto's atmosphere has passed away at age 67.
S&T's Audio Sky Tour for March 2011
This will be a month of transition, celestially speaking: spring and daylight-saving time arrive for northern skywatchers, Jupiter makes an exit, and Saturn is waiting in the wings.
Game Plan for NASA's Planetary Missions
If you had billions of dollars to spend on interplanetary spacecraft, which ones would you choose and why? After an exhaustive, two-year assessment, a blue-ribbon panel turned over its top picks to NASA.
Kepler Finds Planets in Tight Dance
It can get pretty crowded in the solar systems discovered by NASA's Kepler observatory. In one case, four candidate worlds are locked in a tight orbital dance.
A New Take on the Spotless Sun
A trio of researchers believe a slow-moving conveyor belt between the Sun's equator and its poles is responsible for the recent years-long absence of sunspots.
Double Whammy on Mars
On January 10th, NASA's Mars Reconnaissance Orbiter spotted twin craters joined at the rim — the consequence of equal-size halves of a single object striking the planet together.
A Half-Gigabyte View of the Moon
This week NASA scientists unveiled a view of the lunar nearside that measures an astounding 24,000 by 24,000 pixels.
Tour March's Sky! | February 24th, 2011
This will be a month of transition, celestially speaking: spring and daylight-saving time arrive for northern skywatchers, Jupiter makes an exit, and Saturn is waiting in the wings.
Boston's Planetarium Gets a Makeover
Looking spiffy after a year-long, $9 million renovation, New England's largest sky theater can now transport audiences to the edge of the universe in style.
