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

6 days ago · During its extended mission, Juno’s trajectory passes by Io every other orbit, flying over the same part of the moon each time. Previously, the spacecraft made close flybys of Io in December 2023 and February 2024, getting within about 930 miles (1,500 kilometers) of its surface.The latest flyby took place on Dec. 27, 2024, bringing the spacecraft within about 46,200 miles (74,400 kilometers ...

6 days ago · The source of Io’s torment: Jupiter. About the size of Earth’s Moon, Io is extremely close to the mammoth gas giant, and its elliptical orbit whips it around Jupiter once every 42.5 hours. As the distance varies, so does the planet’s gravitational pull, which leads to the moon being relentlessly squeezed.

5 days ago · Io is about the size of Earth’s moon, and orbits extremely close to the mammoth gas giant. And it whips around Jupiter once every 42.5 hours in an elliptical (oval-shaped) orbit. As the distance ...

Dec 14, 2024 · Flybys of Jupiter’s fiery moon Io, carried out by NASA’s Juno spacecraft, are helping to solve the enduring mystery of why the small moon is the most volcanically active body in our solar...

5 days ago · The source of Io's torment: Jupiter. About the size of Earth's moon, Io is extremely close to the mammoth gas giant, and its elliptical orbit whips it around Jupiter once every 42.5 hours. As the ...

Dec 12, 2024 · The north polar region of Jupiter’s volcanic moon Io was captured by NASA’s Juno during the spacecraft’s 57th close pass of the gas giant on Dec. 30, 2023. Data from recent flybys is helping scientists understand Io’s interior.

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.

Apr 18, 2024 · Scientists on NASA’s Juno mission to Jupiter have transformed data collected during two recent flybys of Io into animations that highlight two of the Jovian moon’s most dramatic features: a mountain and an almost glass-smooth lake of cooling lava.

Apr 18, 2024 · Io is the most volcanic body known to science, and researchers have puzzled over its history for years. A new report suggests it was born this way. This image revealing the north polar region of...