Slightly larger than Earth's Moon, Io is the fourth-largest natural satellite in the Solar System, has the highest density of any natural satellite, the strongest surface gravity of any natural satellite, and the lowest amount of water by atomic ratio of any known astronomical object in …

Jan 29, 2025 · Only slightly larger than Earth’s Moon, Io is about one-quarter the diameter of Earth itself. Jupiter's turbulent moon, Io, captured during a close approach by NASA's Juno spacecraft on Dec. 30, 2023. Use this tool to compare Io to Earth, and other worlds.

Io is made mostly of silicate rocks, and its surface is painted with sulfur particles from the volcanoes and frosts that are created as the atmospheric gases freeze out and fall to the ground. Robotic missions to Io could study its volcanism in closer detail.

Mar 11, 2025 · Io is about 3,640 km (2,260 miles) in diameter, a little larger than Earth ’s Moon. Its average density of about 3.52 grams per cubic cm is characteristic of rocks but not ices. Io has a very tenuous atmosphere, composed in large part of sulfur dioxide.

Oct 26, 2024 · Io is Jupiter's third largest moon, and the most volcanically active world in the solar system. Io was discovered on Jan. 8, 1610, by Galileo Galilei, along with Jupiter's three other largest moons: Europa, Ganymede. and Callisto.

Oct 26, 2000 · This mosaic of images acquired by NASA's Galileo spacecraft on February 22, 2000, shows the highest resolution view ever obtained of the surface of Jupiter's volcanic moon Io, 5 to 6 meters (16 to 20 feet) per picture element.

Oct 26, 2022 · Io — Jupiter's fifth moon — is the most volcanically active body in the solar system. Io's surface is peppered with hundreds of volcanoes, some spewing sulfurous plumes hundreds of miles...

Io is a moon of the planet Jupiter. It is Jupiter's third biggest moon with a diameter of 3642 km, slightly bigger than Earth 's moon. Io has about 400 active volcanos. It is the most volcanically active body in the Solar System.

Io is the innermost of Jupiter’s four largest moons, which are also known as the Galilean moons (Europa, Ganymede, and Callisto are the remaining three). Because it’s the closest moon to its massive host planet, Io feels a strong gravitational pull as it orbits Jupiter.

Nov 29, 2023 · Io, the mesmerizing moon of Jupiter, stands as a celestial wonderland of volatile volcanic activity, stunning colors, and ever-changing landscapes. Its vibrant surface, adorned with volcanic plumes and sprawling lava flows, showcases the intensity of the tidal forces shaping this enigmatic world.