Mars to lose its largest moon, Phobos, but gain a ring
In 10-20 million years, the moon will get so close to Mars that it'll be shredded into a ring

Date:
November 24, 2015

Source:
University of California - Berkeley

Summary:
Mars' largest moon -- one of only two in our solar system moving inward towards its planet -- will eventually be torn apart by tidal forces and distributed in a ring around the planet, a study of the cohesiveness of Phobos has concluded. This would take about 10-20 million years, and the ring will persist for up to 100 million years before the dust falls into Mars' atmosphere and burns up as 'moon' showers.

Exerpt:
Black and Mittal, both in UC Berkeley's Department of Earth and Planetary Science, were drawn to the question of what might happen to Phobos because its fate is expected to be so different from that of most other moons in our solar system.

"While our moon is moving away from earth at a few centimeters per year, Phobos is moving toward Mars at a few centimeters per year, so it is almost inevitable that it will either crash into Mars or break apart," Black said. "One of our motivations for studying Phobos was as a test case to develop ideas of what processes a moon might undergo as it moves inward toward a planet."

Full Article:
http://www.sciencedaily.com/releases/2015/11/151124143506.htm