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the collision of Phobos
Mars has two moons: Phobos and Deimos. Both are irregular and are believed to have been captured from the nearby asteroid belt.
Phobos always shows the same face of Mars, because of the tidal forces exerted by the planet on its satellite. This same force causes Phobos to come increasingly closer to Mars, a situation that will cause their collision in about 50 to 100 million years.
How can I calculate, given appropriate data, the estimated time at which Phobos collides with Mars?
