Ocean world near Saturn top contender for life beyond Earth

A tiny, ice-encrusted ocean world orbiting Saturn is now a hotter-than-ever candidate for potential life.

NASA's Cassini spacecraft has detected hydrogen molecules in the geysers shooting off the moon Enceladus, possibly the result of deep-sea chemical reactions between water and rock that could spark microbial life, scientists announced Thursday.

NASA and others are quick to point out this latest discovery does not mean there's life on Enceladus (ehn-SEHL'-uh-duhs), but that there may be conditions favorable for life.

7 Earth-size worlds found orbiting star; could hold life

For the first time, astronomers have discovered seven Earth-size planets orbiting a single nearby star — and these new worlds could hold life.

This cluster of planets is less than 40 light-years away in the constellation Aquarius, according to NASA and the Belgian-led research team who announced the discovery Wednesday.

Vera Rubin, who did pioneering work on dark matter, dies

Vera Rubin, a pioneering astronomer who helped find powerful evidence of dark matter, has died, her son said Monday.

She was 88.

Allan Rubin, a professor of geosciences at Princeton University, said his mother died Sunday night of natural causes. He said the Philadelphia native had been living in the Princeton area.

Vera Rubin found that galaxies don't quite rotate the way they were predicted, and that lent support to the theory that some other force was at work, namely dark matter.

China begins operating world's largest radio telescope

The world's largest radio telescope began searching for signals from stars and galaxies and, perhaps, extraterrestrial life Sunday in a project demonstrating China's rising ambitions in space and its pursuit of international scientific prestige.

Beijing has poured billions into such ambitious scientific projects as well as its military-backed space program, which saw the launch of China's second space station earlier this month.

Little Mercury a black dot as it crosses vast face of sun

For the first time in 10 years, Mercury passed directly between the Earth and sun on Monday, resembling a black dot against the vast, glowing face of our star.

Many stargazers turned to the Internet as NASA provided close-to-real-time images of the 7½-hour trek, courtesy of the Solar Dynamics Observatory.

Although the solar system's small, innermost planet appeared to be trudging along, it actually was zooming past the sun at 106,000 mph.