how many moons does jupiter have

Jupiter has 115 officially recognized moons. According to NASA Science, the International Astronomical Union officially recognizes this count, though the planet is surrounded by thousands of smaller untracked objects.

The Four Galilean Moons

The largest and most well-known moons were discovered by Galileo Galilei in 1610.

• Ganymede. This is the largest moon in our entire solar system and is bigger than the planet Mercury.
• Callisto. Its heavily cratered surface shows very little current geological activity.
• Io. This inner moon is the most volcanically active body in the solar system.
• Europa. Scientists believe a liquid-water ocean lies beneath its frozen crust, making it a primary target for NASA’s Europa Clipper mission.

Smaller and Captured Moons

The remaining 111 moons vary greatly in size and orbit.

• Inner moons. A few small inner moons help supply material to form Jupiter’s faint ring system.
• Outer irregular moons. Many of the smaller outer moons are likely asteroids that were captured by Jupiter’s massive gravity, resulting in tilted or backward orbits.
• Unconfirmed objects. Beyond the 115 confirmed moons, Wikipedia notes that hundreds of tiny, kilometer-sized outer moonlets have been briefly spotted