Jupiter

Jupiter is the fifth planet from the Sun, and the largest in the solar system, by far — more than twice as massive as the other planets combined.

Facts About Jupiter

Jupiter is the largest and oldest planet in our solar system.

If Jupiter was a hollow shell, 1,000 Earths could fit inside. But the "King of Planets" is no lumbering giant — Jupiter has the shortest day in the solar system, taking about 9.9 hours to spin around once on its axis.

NASA’s Juno spacecraft imaged Jupiter’s Great Red Spot on Feb. 12, 2019.

Enhanced image by Kevin M. Gill (CC-BY) based on images provided courtesy of NASA/JPL-Caltech/SwRI/MSSS

Exploring Jupiter

The first detailed observations of Jupiter were made by Galileo Galilei in 1610 with a small, homemade telescope.

More recently, this planet has been studied by orbiters, probes, and spacecraft passing by on their way to other worlds. NASA’s Juno spacecraft currently is studying the giant planet from orbit. Europa Clipper launched on Oct. 14, 2024, to study Jupiter's icy moon, Europa.

Europa Clipper spacecraft lifts off from Kennedy Space Center in Florida on Oct. 14, 2024.

SpaceX

Moons of Jupiter

Jupiter has 95 moons that have been officially recognized by the International Astronomical Union.

But the number doesn't capture the complexity of the Jovian system of moons, rings and asteroids. The giant planet has thousands of small objects in its orbit.

This composite image shows the edge of Jupiter, and Jupiter's four largest moons. From top to bottom, the moons shown are Io, Europa, Ganymede, and Callisto.

Jupiter Resources

Explore a curated collection of Jupiter resources.

These resources include activities that can be done at home, as well as videos, animations, posters, and online interactives.

NASA's Juno spacecraft saw this striking vista during a close flyby of Jupiter.

Red, White & Blue through every challenge

Juno: 10 Years in Orbit around Jupiter

Five years after leaving Earth to make the 1.7 billion-mile journey (2.8 billion kilometers), the Juno spacecraft entered orbit around Jupiter on July 4, 2016. Through an intricate and critical series of procedures — which could have doomed the mission, but the spacecraft performed almost flawlessly — Juno maneuvered into the grasp of the King of Planets, ready to unlock its secrets. The orbiter has been capturing breakthrough science and breathtaking images ever since.

Final missing signature from Jupiter’s four largest moons

Unlike Earth’s Moon and our planet’s northern lights, the massive, shimmering auroras above Jupiter’s poles carry signatures that the planet’s largest moons leave in the atmosphere. Before NASA’s Juno mission, three of Jupiter’s four largest moons, known as Galilean moons — Io, Europa, and Ganymede — were shown to produce these distinct auroral signatures. But Callisto, the most distant of the Galilean moons, remained a mystery.

Juno capturing the marks on Jupiter of all four Galilean moons. The auroras related to each are labeled Io, Eur (for Europa), Gan (for Ganymede), and Cal (for Callisto).