SUNSET: 
A New Radio Observatory in Space
With the long-awaited (and long-overdue) launch of Russia's Spektr-R spacecraft, radio astronomers can look forward to resolving never-before-possible details in the dynamic cores of active galaxies and other exotic targets.
Dawn Arrives at Vesta
NASA's spacecraft Dawn entered orbit around Vesta on July 16th and is preparing for a year's observation of the second-largest body in the asteroid belt.
Hail and Farewell, Atlantis!
Sky & Telescope's veteran space-science reporter muses on his long association with the Space Shuttle after witnessing its final launch at 10:29 a.m. EDT on Friday, June 8, 2011.
Will the Webb Telescope Be Canceled?
NASA's next-generation space observatory is already woefully over budget and behind schedule. But if Congressional money-minders have their way, the project will be killed outright in the months ahead.
The Star That Changed Our Universe
Modern observers have revisited a dim variable star in the Andromeda Galaxy whose discovery in 1923 rocked the astronomical world.
Odd Couple: Phobos and Jupiter
Recently two very different bodies made a joint appearance, as viewed by the stereo camera aboard the European orbiter Mars Express.
Messenger Reveals Mercury Anew
Already a fourth of the way through its basic mission, NASA's well-equipped orbiter has found that the "Iron Planet" is far different than planetary scientists expected.
Kepler's Exoplanets: A Progress Report
The Kepler exoplanet-hunting mission got top press-conference billing at the American Astronomical Society convention in Boston. But some reporters left wanting more.
Vesta Ahoy!
As Dawn closes in on Vesta, pictures from the spacecraft’s cameras are helping engineers steer it to its July rendezvous.
Gravity Probe B: Relatively Important?
It took five decades and $750 million for the Gravity Probe B mission to check, once again, that Einstein’s theory of general relativity is right. Was it worth it?
New Insights on "Tycho's Supernova"
The famous Danish astronomer Tycho Brahe watched a star explode in 1572. Now new observations strongly suggests that there was an accomplice in its demise.
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.
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.
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.
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.
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.
Stardust's Date With Comet Tempel 1
Low on fuel but right on the money, NASA's Stardust spacecraft visited its second comet earlier today. Scientists are eager to see the crater supposedly punched in the icy nucleus 5½ years ago. One small problem: there's not much of a crater to see.
Get Ready for a Solar-System Bonanza
We already have spacecraft orbiting the Moon, Venus, Mars, and Saturn — and another more than halfway to Pluto. But the year 2011 stands to be one of the busiest ever for new interplanetary missions.
