Phobos is the largest and closest of the two moons of Mars. Because its orbital period is shorter than a Martian day, tidal deceleration has been decreasing its orbital radius at the rate of about 20 metres (66 ft) per century.
By this date, it has passed the Roche limit - the distance within which a celestial body, held together only by its own gravity, will disintegrate due to a second body's tidal forces exceeding the first's gravitational self-attraction.
Phobos begins to break apart. It gradually becomes a ring system over the following 3 million years, with many of these fragments impacting upon Mars itself.
Neptune's largest moon - triton - will share a similar fate.
No comments:
Post a Comment