Mar’s largest moon, Phobos, has an inward-moving orbit that is sending it on a path toward Mars’ gravitational grasp. This could cause the moon to break apart and disintegrate into a planetary ring some 20 million to 40 million years from now, according to a study published Monday in the journal Nature Geoscience.
Researchers used a combination of simulations and models to analyze how Phobos’ orbit may evolve. They took a close look at the physical stresses Mars exerts on Phobos as the moon’s orbit causes it to gradually veer inward.
Phobos is a delicate moon with lots of pores and rubble on its surface which could contribute to it eventually crumbling to pieces under the red planet’s powerful gravitational pull. These fragmented pieces would then orbit Mars, forming a planetary ring.
Saturn’s rings are thought to have formed in a similar way, and some scientists speculate that Neptune’s moon Triton might be falling apart causing it to reach the same doomed fate.
The destruction of a planet’s moon or another passing object, such as an asteroid or comet, is one of the most common ways in which planetary ring systems form.