This week: "Cavemen" hang on in China, comets crash, man-size fish caught, passenger spaceship design unveiled, and mud fills classroom.

Stunning color images offer new evidence that plentiful water once percolated through Martian bedrock—and new hints as to where life might be hiding.

Saturn's moon Enceladus is sandblasting other nearby moons with giant geysers of ice, making the moons appear brighter, research shows.

Mars may still house large reservoirs of the water and carbon dioxide that once formed the planets ancient atmosphere, new research suggests.

An exotic form of diamond found only in Brazil and the Central African Republic may have brought to Earth by an asteroid, new research suggests.

Comet McNaught—the brightest comet in 40 years—could be the last thing sky-watchers see if they aren't careful, astronomers warn.

The latest x-ray image of the remains of an exploded massive star reveals that the star died in a thermonuclear blast, astronomers say.

A new project plans to detect low-frequency signals sent by alien civilizations—from military radar to the ET version of talk radio.

The Internet giant has signed on to help make data from what will be the largest sky survey readily available to the public.

The discovery of eight tiny galaxies near our own may provide scientists with insights into the structure of the universe.

Based on a new infrared image, the iconic space formation was likely destroyed 6,000 years ago—but we won't see it happen for another thousand years.

The first observed trio of these enormous, hyperactive black holes offers insights into galaxy collisions that took place in the cosmic past.

A pulsating star, or pulsar, in the Crab Nebula may be the first known celestial body to have more than two poles, astronomers said Monday.

Scientists have created a detailed, three-dimensional map of dark matter's evolution over time—revealing that the mysterious substance forms the scaffolding for stars and galaxies.

Titan has lakes of methane and a hydrological cycle that resembles in uncanny detail the one found on Earth, a new study finds.