Learn more about the hunt for bacteria on Mars and how astronauts will need to make sure they aren't bringing any dormant ...

Advances in technology have reopened the debate over terraforming Mars, shifting it from an impossible dream to a long-term scientific and ethical question.

For years, scientists have been intrigued by mysterious dark streaks running down the slopes of Martian cliffs and craters. These marks, called slope streaks and recurring slope lineae (RSLs), have ...