Galaxies

Two intrepid galaxies dash past the Milky Way—and dazzle astronomers with their beauty and brilliance as new observations reveal why the pair is so flamboyant

An incomplete version of Chile's ALMA telescope array found that star formation was in full swing earlier than had been thought. John Matson reports

Comet Pan-STARRS will take about 110,000 years to orbit the sun after this first swing through the inner solar system

New observations by NASA's Curiosity rover suggest that microbial life could have survived on Mars in the distant past

After nearly four years mapping the cosmos, the Herschel Space Observatory is expected to exhaust its vital supply of liquid helium coolant within the next few weeks

Low-mass binary stars could make the best hosts for alien life because their combined energy extends the habitable region farther away than would exist around a single star

The upcoming cosmic spectacle should offer scientists a chance to test some of their theories about how black holes accrete mass

NASA's Mars Reconnaissance Orbiter used radar to find the underground Martian channels

NASA's MESSENGER probe has imaged every square meter of the planet's surface

Although unlikely, there is a small chance the Comet Siding Spring, an estimated eight to 50 kilometers in diameter, could collide with Mars in October 2014

A plan is afoot for China and Europe to collaborate on a space station that could be operational by 2020

The Dragon capsule is due to deliver 544 kilograms of scientific experiments and supplies to the space station on Saturday