Mars moons may have formed from collision

[Brian G Turner]

Mars moons may have formed after collision with Pluto-like world

Phobos and Deimos may be a chip off the old Martian block. The Red Planet’s tiny, misshapen moons are often thought to be captured asteroids, but an alternative theory suggests they are shrapnel left over from an ancient impact on Mars. Now we have a model showing how this could have happened.