ComradeSharkfucker
JennaR8rI thought moons & planets always appear generally round from a distance. This lumpy irregularly-shaped Phobos looks like an asteroid.
Both Mars’ moons (Phobos and Deimos) are asteroids. They’re really small.
“Hydrostatic equilibrium” is the term (I think) for when a body is massive enough for it’s gravity to pull it into a spheroid. E.g. Ceres is about 950km in diameter and is ‘round’.
Hmm today I learned that asteroids can also be moons! Was it just floating around freely like any other asteroid until it got caught into the orbit of Mars, then got stuck there forever?
Probably. It does happen.
Fun fact. Triton, Neptune’s largest moon, orbits the wrong way which means it was gravitationally captured by Neptune at some point.