A Chihuahua wins a canine costume contest, a tiger cub stalks a pumpkin, and more in our weekly update of animal photos.

An American space tourist returns to Earth, India launches first mission to the moon, and more in our weekly update of space photos.

A Chihuahua struts during a Halloween dog show, a vendor strings marigolds for a Hindu festival, and more in our weekly update of culture photos.

A supersonic car, a brand-new mosque, and Los Angeles wildfires are captured in some of the week's best photos.

The tiny-limbed creature is the first of 14 new species to be identified from a January expedition to Brazil's central savanna.

From European missionaries to WWII planes, a newfound collection of rock art in northern Australia chronicles Aborgine culture through the centuries.

A Persian leopard cub looks into the camera, a two-headed turtle is discovered, and more in our weekly update of animal photos.

A 12-billion-year-old cosmic collision is discovered, Santa Ana winds drive smoke across the Pacific, and more in our weekly update of space photos.

Brazilian Christians pray before a mass baptism, a lizard sculpture eyes chefs at the Culinary Olympics, and more in our weekly update of culture photos.

A 2008 expedition to the Xe Bang Fai River cave in the central part of the country uncovers "spectacular formations," and some of the largest cave rooms on Earth.

From "eclectic" medieval towns in Belgium to McMansions encroaching on Civil War sites in Virginia, a new annual survey ranks the most authentic--and most imperiled--historic places.

Fossil hunters searching woods behind a suburban Massachusetts strip mall discovered the impression, which one expert described as "winning the lottery."

A mining boom in Mongolia is threatening to destroy the country's essential watersheds and is forcing nomadic herders to abandon their land and traditional way of life, environmentalists warn.

Boxed penguins, blazes in L.A., a ball of "lightning," and a big shipwreck are captured in some of the week's best news photos.

A beetle dances on a pin, nanotubes glow like a microscopic sun, drugs yield crystal rainbows, and more in the top ten micro-photos of the year.