17. The Asteroid Belt
“If you took all of the asteroids in the asteroid belt between Mars and Jupiter and mashed them together into a single big object, it would only amount to 4% the mass of Earth’s Moon. The largest asteroid, Ceres, accounts for about 1/3 of the total mass of the asteroid belt.” – u/itsamamaluigi
Thanks to Reddit user itsamamaluigi, all the movie scenes with interstellar fights between asteroids are so ruined!