How Many Moons Does Jupiter Have?
QUICK ANSWER
Jupiter has 115 confirmed moons as of April 2026, including the four large Galilean moons discovered by Galileo in 1610: Io, Europa, Ganymede, and Callisto. Saturn recently surpassed Jupiter for the most known moons in the solar system, but Jupiter still has the four biggest.
Jupiter has more than 100 known moons, and the number keeps growing. Until recently, Jupiter held the record for most moons in the solar system, but Saturn passed it in 2023 and has been adding more ever since. Even so, Jupiter's four biggest moons are in a class of their own.
How many moons does Jupiter actually have?
As of April 2026, Jupiter has 115 confirmed moons, according to the Minor Planet Center. According to NASA, the count has grown significantly over the past few years as astronomers have improved their ability to detect very small, dim objects orbiting the planet. Most of Jupiter's moons are tiny (less than 10 miles across) and irregular in shape, likely captured asteroids rather than original satellites that formed alongside Jupiter.
What are the Galilean moons?
The four largest moons of Jupiter, discovered by Galileo Galilei in January 1610. They are Io, Europa, Ganymede, and Callisto. Each is a substantial world in its own right: Ganymede is the largest moon in our solar system, larger than the planet Mercury. Io is the most volcanically active body in the solar system. Europa has a global subsurface ocean beneath its icy crust. Callisto has one of the most heavily cratered surfaces in the solar system. Galileo's discovery was crucial evidence that not everything orbits Earth.
Doesn't Jupiter have the most moons?
Not anymore. Saturn surpassed Jupiter in 2023 with the discovery of dozens of new small moons, and the gap has only widened since. As of 2026, Saturn has 285 confirmed moons compared to Jupiter's 115. The difference comes down to ongoing observation campaigns: most newly discovered moons around both planets are small, dim, and were simply too faint to detect with older telescopes. Both planets likely have many more moons still waiting to be found.
Where did Jupiter's moons come from?
Two groups, two origins. The eight innermost moons (including the Galilean four) probably formed alongside Jupiter from the same disk of gas and dust, orbiting close to the planet's equatorial plane in regular paths. The rest are mostly irregular outer moons, captured asteroids or comets that wandered too close to Jupiter and got trapped by its gravity. Many of the irregular moons orbit Jupiter backwards or at steep angles, the hallmark of captured objects rather than home-grown satellites.
Jupiter has 115 known moons as of 2026, with the four Galilean moons standing out as some of the most interesting bodies in the solar system. Saturn now holds the record for moon count, but Jupiter's collection is still the most varied and scientifically rich. Expect both totals to keep climbing as telescopes improve.
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