Io orbits the planet Jupiter, which itself orbits the Sun at a distance of 484 million miles (778 million kilometers).

2024年5月16日 · The speed needed for an object to break away from the gravitational pull of a planet or moon.

1995年11月9日 · Io's insides are heated instead by a tidal interaction process between Io, Jupiter and two other moons of Jupiter named Ganymede and Europa. Because Ganymede and Europa gravitationally tug on Io, Io's orbit around Jupiter is not perfectly circular.

Triton is the largest of Neptune's 13 moons. It is unusual because it is the only large moon in our solar system that orbits in the opposite direction of its planet's rotation―a retrograde orbit. Scientists think Triton is a Kuiper Belt Object captured by Neptune's gravity millions of years ago.

Orbit and Rotation. Europa orbits Jupiter every 3.5 days and is locked by gravity to Jupiter, so the same hemisphere of the moon always faces the planet. Jupiter takes about 4,333 Earth days (or about 12 Earth years) to orbit the Sun (a Jovian year).

Europa rotates once on its axis and completes one orbit of Jupiter every 3.5 Earth days, so the same side of Europa always faces Jupiter.

2025年1月9日 · The Jovian moon Io is likely the most geologically active body in the solar system, offering insight into tidal heating, volcanic processes, and other phenomena. However, its location within Jupiter''s radiation belt presents significant engineering challenges that must be addressed to enable future missions to Io.

2025年1月9日 · NASA’s real-time science encyclopedia of deep space exploration. Our scientists and far-ranging robots explore the wild frontiers of our solar system.

Jupiter's four largest moons – Io, Europa, Ganymede, and Callisto – were first observed by the astronomer Galileo Galilei in 1610 using an early version of the telescope. These four moons are known today as the Galilean satellites, and they're some of the most fascinating destinations in our solar system.

2008年10月9日 · Enceladus orbits Saturn twice every time Dione, a larger moon, orbits once. Dione’s gravity stretches Enceladus’ orbit into an elliptical shape, so Enceladus is sometimes closer and other times farther from Saturn, causing tidal heating within the moon.