Life on Mars

The discovery of tiny balls and tunnels inside a Martian meteorite has rekindled the debate over whether the Red Planet was teeming with primitive life millions of years ago.

From extrasolar planets to extraterrestrial neutrinos, these scientific findings have made sure that 2013 has been an unforgettable year.

Based on tests of microbes under Marslike conditions, an expert thinks airborne microbes could grow 30 miles above Earth's surface, in the stratopause.

A boron-rich rock from Mars suggests the Red Planet once had the right chemistry to give rise to RNA.