There are 67 known moons of Jupiter. This gives Jupiter the largest number of moons with reasonably secure orbits of any planet in the Solar System. The most massive of them, the four Galilean moons, were discovered in 1610 by Galileo Galilei and were the first objects found to orbit a body that was neither Earth nor the Sun. From the end of the 19th century, dozens of much smaller Jovian moons have been discovered and have received the names of lovers, conquests, or daughters of the Roman god Jupiter, or his Greek equivalent, Zeus. The Galilean moons are by far the largest and most massive objects in orbit around Jupiter, with the remaining 63 moons and the rings together comprising just 0.003% of the total orbiting mass.