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 23, 2023 · Scientists say that Io may have once had more water, perhaps even similar to the ocean moons Europa and Ganymede. But then it lost all or most of it over billions of years. As Schulze-Makuch...

Oct 26, 2024 · Jupiter's rocky moon Io is the most volcanically active world in the solar system, with hundreds of volcanoes, some erupting lava fountains dozens of miles (or kilometers) high. Io’s remarkable activity is the result of a tug-of-war between Jupiter's powerful gravity and smaller but precisely timed pulls from two neighboring moons that orbit ...

Jan 29, 2025 · 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. Jupiter's moon Io, its night side illuminated by reflected sunlight from Jupiter, or "Jupitershine."

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.

Jul 8, 2017 · Of Jupiter’s Galilean moons, Io is the closest to the planet at an average distance of 422,000 km (262,219 miles), and is the moon with the highest density. It is also the solar system object with the least amount of water, and the only object other than the Earth that is known to be volcanically active.

Dec 20, 2024 · Io, Jupiter’s innermost moon, was purported to have one made of basalt and bits of sulfur just under its surface, powering its volcanic eruptions. But according to a study published in Nature...

Feb 10, 2024 · Unlike most moons in the outer Solar System, Io lacks a substantial water ice component, which is a direct consequence of its intense volcanic activity. Io has a diameter of about 3,643 kilometers (2,264 miles), making it slightly larger than Earth’s moon.

5 days ago · Juno spacecraft data reveals that tidal forces deform the moon differently than expected if a magma ocean were present. Instead, Io’s mantle appears mostly solid, challenging old models and hinting at a more complex interior. A new study published in Nature challenges previous claims that Io has a shallow, global magma ocean beneath its surface.

Nov 20, 2023 · Solving this mystery could also help reveal how Io’s lunar sibling Europa and other icy moons manage to harbor vast, potentially habitable liquid-water oceans despite the outer solar system’s...