Jupiter is the fifth planet from our Sun and is, by far, the largest planet in the solar system – more than twice as massive as all the other planets combined. Jupiter's stripes and swirls are actually cold, windy clouds of ammonia and water, floating in an atmosphere of hydrogen and helium.

Jupiter orbits about 484 million miles (778 million kilometers) or 5.2 Astronomical Units (AU) from our Sun (Earth is one AU from the Sun).

Jupiter's menagerie of moons includes the largest in the solar system (Ganymede), an ocean moon (Europa) and a volcanic moon (Io). Many of Jupiter's outer moons have highly elliptical orbits and orbit backwards (opposite to the spin of the planet).

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Nov 29, 2001 · A recent image from NASA's Galileo spacecraft adds evidence to a theory that Callisto, the outermost of Jupiter's four large moons, may hold an underground ocean.

Jupiter’s moons Io, Europa, and Ganymede are in what is called a resonance – every time Ganymede orbits Jupiter once, Europa orbits twice, and Io orbits four times.

Saturn is the sixth planet from the Sun and the second-largest planet in our solar system. Like fellow gas giant Jupiter, Saturn is a massive ball made mostly of hydrogen and helium. Saturn is not the only planet to have rings, but none are as spectacular or as complex as Saturn's. Saturn also has dozens of moons.

Nov 9, 1995 · Like our own Moon, some of the Jupiter's 53 known moons are covered with impact craters, showing where meteorites smashed into the surface. But Io is covered with hundreds of volcanic craters which continually spew forth fresh material, resurfacing the …

Jan 9, 2025 · Explore NASA's real-time science encyclopedia and compare the sizes of planets in our solar system.

Dec 13, 2000 · Overcoming severe radiation damage, the redoubtable orbiter has deployed a probe into Jupiter's atmosphere; studied the hottest volcanoes in the Solar System on Jupiter's moon Io; discovered evidence of subsurface oceans on the moons Europa and Ganymede; and provided new insights into the giant planet's stormy atmosphere, gigantic magnetosphere ...