Earth only has one moon, but dozens of natural satellites revolve around Jupiter, the biggest planet in our solar system. And new members in the Jupiter posse are still being discovered. Back in December 2022, a team of astronomers published orbits for 12 previously unreported moons around the planet. This brings the current tally of moons around Jupiter to 92 and puts Jupiter once again in the lead for most moons orbiting a planet. The count became official Jan. 20, 2023 and was announced in February 2023.
Scott S. Sheppard of the Carnegie Institute for Sciences has been leading a search for new objects in the distant Kuiper Belt, an enormous ring of debris that lies beyond Neptune, and was part of the team that found these moons. Sheppard and his colleagues also found 12 previously unknown moons around Jupiter in 2018, as well as 20 new satellites around Saturn in 2019.
In 1610, the great astronomer Galileo Galilei noticed four heavenly bodies that appeared to revolve around Jupiter. Named Io, Europa, Ganymede and Callisto, these are Jupiter's biggest moons by far — and they were the first to be discovered. As stargazing technology grew more sophisticated, it became clear that the quartet had lots of company. These latest moons are small and have orbits of one or two years, unlike the "big four" which are huge and have orbits of less than 17 days.
Jupiter had always had the most moons in the solar system, until 2019 when Saturn temporarily took over that crown with 82 moons. Currently, Saturn has 83 moons. Uranus boasts 27 and Neptune has 14. Mars, our beloved next-door neighbor, possesses two satellites: Deimos and Phobos. And if that's making you feel insecure about Earth's lonely moon, at least you can take solace in the fact that Mercury and Venus are totally moon-less.
There's a reason why Jupiter has so many satellites while other planets — ours, for instance — have so few. It all comes down to gravity.