The four planets in the Gliese system, orbiting a star dimmer than our sun some 20 light-years away,
include the newly found Gliese 581 e (foreground)—a rocky place just twice Earth's mass—and 581 d, which could harbor liquid water.
The launch that sent NASA's Kepler spacecraft streaking starward. Just south of Florida's Cape Canaveral.
Kepler's mission is to keep watch over more than 100,000 candidate stars for signs of Earth-size planets.
A mellow southern elephant seal bull keeps cool under a flipperful of sand.
But photographer Paul Nicklen was attacked while snorkeling off a breeding beach.
"One tried to crush me," he says of a four-ton male.
Using the housing of his underwater camera as a shield, he managed to escape with only sprained wrists.
Two centuries ago, such encounters were almost always fatal—for the seal—but no longer.
Once a killing ground, South Georgia is now a sanctuary.
Antarctica—Cliffs higher than a hundred feet mark the edge of the Ross Ice Shelf, a glacier-fed slab the size of France connected to the Antarctic coast.
Fissure lines near the edge show where the next iceberg may calve.
(Did you notice how small the people are in ther right hand corner?)
Simonos Petras monastery was founded in 1257 more than 800 feet above the Aegean Sea.
It is one of 20 monasteries on the steep-sloped peninsula, a popular pilgrimage site sometimes called the Christian Tibet.
The Antarctic fur seal spends the winter at sea and comes ashore in summer to breed.
Once dangerously depleted by hunting, the species now numbers in the millions—95 percent of which haul out on the breeding beaches of South Georgia.
A penguin-speckled iceberg floats in frigid grandeur off South Georgia.
This remote British outpost in the far South Atlantic is a haven for millions of seabirds and seals.
Religious traffic moves through the Taklimakan Desert in May during the Imam Asim festival.
Uygurs from across Xinjiang walk a path that ends at the mazar, or shrine, of an 11th-century Islamic martyr who died fighting Buddhist forces, according to legend.