... Mimas: Small Moon with A Big Crater . ... Mimas is one of the smaller moons of Saturn but shows one of the largest impact craters! ... On July 20th, 1969, a human first set foot on the Moon. ... From this recent picture by the Hubble Space Telescope, astronomers have estimated its mass is just high enough for it to fuse hydrogen into helium in its core. The Small Cloud of Magellan . ... The Magellanic Clouds are small irregular galaxies orbiting our own larger Milky Way spiral galaxy. ...