721–740 of 793 results

Solar System

The Sun Really Rocks!

Newly released video shows that the entire Sun shimmies and shakes in the aftermath of a big solar flare.

Distant Pioneer

Space Missions

"Pioneer Anomaly" Solved?

The first spacecraft to reach the outer solar system have been mysteriously slowing down for decades. Put aside the exotic explanations; it may be just a matter of heat.

Space Missions

Phobos Gets a Close-up

The small army of spacecraft now operating on and around Mars don't spend all their time watching the Red Planet. Check out this just-released view of one of Mars's moons.

Space Missions

What's Inside Enceladus?

In a daring dash over the south pole of Enceladus, the Cassini orbiter found organic molecules gushing from icy fractures on the Saturnian moon's surface — and hints that a reservoir of liquid water might exist deeper down.


A Record-Breaking Gamma-Ray Burst

The visible-light glow of a gamma-ray burst briefly shone at magnitude 5.4, despite its distance of 7.5 billion light-years — more than halfway across the visible universe.

Space Missions

Titan's Free-Floating Crust

Saturn's giant moon isn't spinning the way a well-behaved satellite should — and some scientists argue that this deviant behavior is due to a global ocean hidden beneath its icy crust.


A Rich Protoplanetary Soup

Infrared observations reveal a star with a protoplanetary disk infused with helpful organic compounds.

Space Missions

Cassini Gets a Face Full of Water

Who would have guessed that a decade after Cassini headed to Saturn, mission scientists would be flying it through an ice volcano's plume?

Solar System

Genesis Finding: Earth Has a Problem

Even as the Genesis spacecraft lay in a crumpled heap on the ground after its reentry chute malfunctioned in September 2004, its scientists remained confident that they would salvage the mission and answer fundamental questions about how the solar system formed. Now they have — and the results have already sent cosmochemists back to the drawing board.

Space Missions

Getting To Know Mercury

Planetary scientists have gathered in Houston, Texas, to get the latest news on what NASA's Messenger spacecraft learned when it zipped past the innermost planet two months ago.

Space Missions

Ring Around a Saturn Moon?

During a close flyby of Saturn's largest icy moon in late 2005, several instruments aboard Cassini sensed (but didn't actually "see") what appears to be a trio of thin rings and a dust disk surrounding Rhea.

Solar System

Four Martian Landslides Caught in the Act

A scarp along the edge of the Martian north polar cap is more active than anyone expected.

Space Missions

Ulysses Says Goodbye

After spending more than 17 years in space, a durable solar sentinel has lost its radio voice and its fuel lines will soon freeze solid.

Space Missions

See the Doomed Spy Satellite!

Until it reenters the atmosphere — whole or in pieces — in the days ahead, you can see the decaying satellite USA 193 with your own eyes. Here's how to find it.

Space Missions

Space-Station Astronomy

Solar telescopes are set to be installed on the International Space Station today. A trio of instruments will be added to the new Columbus module.

Space Missions

NASA Wants You!

The US space agency wants to give its soon-to-be-launched gamma-ray observatory a new name, and it has opened the floor for nominations. Do you have the perfect moniker for the next Great Observatory?

Solar System

Mercury's "Better Half"

When it swept by the innermost planet on January 14th, NASA's Messenger spacecraft showed us a side of Mercury never before seen. After two weeks of intensive study, mission scientists have shared some of the flyby's intriguing results — including views of a "spidery" crater that has them stumped.

Stardust encounters Comet Wild 2

Solar System

A Stardust-Free Comet

When NASA sent a spacecraft to grab samples of a comet and return them to Earth, scientists had high hopes that they'd finally be able to decipher how the solar system formed. Boy, were they wrong!

Solar System

A Bird's-Eye View of the Sun

What's it like to coast high over our star? The European-built spacecraft Ulysses is doing that right now — for its third and likely final time.

Messenger's Mercury

Solar System

Reunion with Mercury

For the first time in nearly 33 years, mission controllers have guided a spacecraft past Mercury, a fire-and-ice world that may hold many keys to the solar system's formation.