Mars may one day have a ring made from its own destroyed moon

One day in the very distant future, Mars may develop a ring composed of its own destroyed moon. Such a notion was recently put forth by a new study looking at its moon Phobos in particular, stating that in about 70 million years the moon could be close enough to the planet to break apart. When that happens, the debris will be pulled into a sort of field around the Red Planet, giving it its own ring.

The entire matter revolves around something called the Roche limit, which is the distance from a planet in which tidal forces will shred another space object being kept together with gravity. In the Red Planet's very distant past, it is possible a ring already existed composed of debris unleashed when a massive asteroid slammed into Mars.

That debris forming the ring would slowly move out into space, where it would clump together and, with gravity's help, turn into a moon. Such may be the case for Phobos, which is currently making its way back toward Mars and, thusly, the Roche limit. Once it reaches that point, the debris will be once again pulled apart to form a ring, fundamentally changing the appearance of Mars as we know it.

According to the research, this process of forming rings and then moons may have happened a handful of times over the last several billion years — between 3 and 7 times depending on where the Roche limit starts. Each previous moon formed by this cycle would have been larger than the one that followed it, as debris is lost each time this process takes place.

SOURCE: EurekAlert