921–940 of 1,107 results

Space Missions

Sparks on Saturn

NASA's Cassini orbiter has finally captured images of lightning storms on the ringed planet.

Solar System

An Amateur's Mercury Odyssey

In 1998 a trio of amateur astronomers slapped a video camera on Mount Wilson's 60-inch reflector and aimed it at Mercury. A decade later, NASA's Messenger spacecraft rediscovered many of the surface features they found.

Solar System

Future Shock From Gliese 710

Is our solar system's Oort Cloud in danger of being stirred up by a passing star? A fresh analysis of Hipparcos observations argue that the answer is most likely "yes" — but not for another 1.4 million years.

Solar System

Zodiacal Light's Mystery Solved

Eerie and elusive, the zodiacal light is created from sunlight glinting off countless dust particles in the inner solar system. At last, astronomers have figured out where all that grit comes from.

Space Missions

Ski Luna!

Geologists once believed the Moon was utterly dry. But just-announced results argue that abundant water ice lies stashed inside lunar craters near the north pole.

Solar System

The New Face of Pluto

Planetary scientists scratching their heads over the dramatic face-lift that this distant little world underwent sometime between 1994 and 2002.

Solar System

A "Whodunit" in the Asteroid Belt

Astronomers are still trying to piece together the story of an object that's looking more and more like the aftermath of the collision between two small asteroids.

Solar System

New Report Spotlights Impact Hazards

A meaty review of the impact hazard facing Earth has just been released by the U.S. National Research Council. The bottom line? If Congress and NASA are serious about finding all the truly threatening asteroids in our planet's vicinity, they'd better fund the search properly.

Solar System

A Strange "Comet" Among the Asteroids

It looks a comet, or at least parts of one, in high-power telescopic images. But in the two weeks since the discovery of P/2010 A2, astronomers are still wondering what's going on with this unusual object and its asteroid sidekick some 95 million miles from Earth.

Space Missions

Saturn's Prometheus: Just Plain Weird!

A remarkable new close-up of a "ring shepherd" reveals muted surface features that make it look more like a giant gray potato than a planetary satellite.

Solar System

A Glint of Sunlight from Titan

With the Sun climbing higher in the northern hemispheres of Saturn and its retinue of moons, the Cassini spacecraft captured a specular reflection off the surface of Titan — and nailed the case for lakes of liquid ethane.

Asteroid occulting a star: artist's concept

Solar System

An Accidental Asteroid Occultation?

It's probably the smallest Kuiper Belt object ever seen, but the evidence is indirect, and not all are persuaded.

Solar System

Has Iapetus Finally Been Solved?

Saturn's bicolored moon, snowy white on one side and coal-black on the other, has puzzled astronomers for three centuries. Planetologists now think they have it all figured out.

Solar System

Cassini Visits a Science-Fiction World

NASA's Cassini probe grabbed three-dimensional views of a landscape of geysers, as the craft sped above an evening twilight zone on Saturn's moon Enceladus.

Solar System

LCROSS Impact Kicked up Lunar Water

It took more than a month of fevered analysis, but NASA scientists are at last convinced that October 9th's crash by the LCROSS spacecraft on a shadowed lunar plain vaporized at least 100 kg of water.

Space Missions

Mercury Throws Geologists a Curve

When NASA's Messenger spacecraft zipped past the innermost planet for a third and final flyby on September 29th, a glitch caused half of the planned observations to be lost. Scientists are thrilled to have the other half — but they're not entirely sure what to make of them.

Space Missions

Strange Brew at LCROSS's Crash Site

NASA scientists haven't said much since a spacecraft and its carrier rocket slammed into a lunar crater on October 9th. One reason might be that they can't believe what they're finding there.

LCROSS on final approach

Space Missions

The LCROSS Impact, Continued

We've added updates our story on the Moon probe that NASA hoped would raise a big dust-and-vapor splash. The debris plume has indeed been seen. But how much information can be extracted from it?

Solar System

Less Ado About Apophis

Now you can make plans for April 13, 2036, without worrying about a giant space rock crashing into Earth and ruining your day.

Solar System

Saturn's New King of the Rings

Faint but real, a newly found ring encircles Saturn out to distances of 11 million miles.