1041–1060 of 1,119 results

Solar System

Of Planets and Palace Elephants

A fourth-grader from Montana bested 800 other contestants to find a new way to remember all 11 major and dwarf planets.

Triple asteroid

Solar System

A Triple Asteroid Threat

After taking aim at a passing asteroid with the Arecibo telescope's powerful radar, astronomers discovered that it has two satellites.

Space Missions

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

Space Missions

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

Mercury, Messenger, and Observers

As the first images are released from Messenger's flyby of the innermost planet, previous ground-based observations are proving to be surprisingly accurate.

Space Missions

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.

Solar System

Mars Dodges a Bullet

Fortified with two months of telescopic tracking, dynamicists say there's now virtually no chance that a small asteroid will strike Mars later this month.

History and Sky Lore

Martian Crater Named for “Chick” Capen

A crater on Mars has been officially named for the American scientist Charles F. Capen.

Solar System

A New Cycle is Dawning

It's nothing more than an inconspicuous blemish in the Sun's northern hemisphere, but a new sunspot has heralded the start of the next 11-year-long cycle of solar activity.

Solar System

Cassini's Popularity Contest

After a month-long contest, the Cassini Imaging Central Laboratory for Operations (CICLOPS) has announced which images of Saturn are fan favorites.

Solar System

Odds of Mars Strike Now 1-in-25

Astronomers have been watching a small asteroid that, they now say, has a 4% chance of colliding with Mars on January 30th.

Solar System

Mars in the Crosshairs?

Astronomers are waiting to see what becomes of a skyscraper-size asteroid that has a 1-in-75 chance of hitting Mars in late January.

People, Places, and Events

Tunguska's Blast: Less is More

Aided by high-def supercomputer simulations, two researchers now argue that small asteroids striking Earth — like what happened over Siberia in 1908 — may pose greater danger than previously believed.

Solar System

David Levy's Binary Asteroid

An otherwise run-of-the-mill, main-belt asteroid named 3673 Levy just got a lot more interesting: It has a tiny moon!

Solar System

Deep Impact's New Assignments

Put to sleep after its smash success in 2005, one of NASA's interplanetary craft is getting a chance to search for extrasolar Earths and to visit a second comet.

Solar System

Earth's Magnetosphere: On the Ropes

A constellation of five identical orbiting probes has detected skirmishes with the solar wind along Earth's magnetospheric front lines.

Solar System

Saturn's Sci-Fi Moons

Just when you thought you'd seen everything the ringed planet has to offer, the Cassini orbiter glimpses bizarre little moons shaped like flying saucers.

Solar System

My Kind of Beauty Contest!

What's the most beautiful image taken by the Cassini spacecraft since it arrived at Saturn? Vote for your favorite today!

Solar System

Lightning on Venus

The world next door seemed hellish enough with an atmosphere 90 times the sea-level pressure on Earth and surface temperature of 900°. Now, scientists say, there's lots of lightning — and what little water it has seems to be escaping to space.