Jupiter’s moon Io, known as the most volcanically active body in the Solar System, with 400 volcanoes and vast lava flows, might not have the global magma ocean scientists once theorized. A new study based on data from NASA’s Juno spacecraft suggests that Io’s geological activity is fueled by localized magma chambers scattered throughout a mostly solid mantle.
Researchers combined images from Juno, gravitational measurements, and historical data on Io’s tidal deformations to challenge the long-held idea of a moonwide magma ocean beneath the surface. Instead, the study points to a solid mantle with pockets of molten magma.
This revelation contrasts with previous theories that magma oceans are common in the early stages of planetary and lunar formation, including Earth’s Moon. The findings could reshape our understanding of how planets and moons evolve.
Io’s volcanic activity is powered by tidal flexing, caused by its elliptical orbit around Jupiter every 42.5 hours. The immense gravitational forces stretch and compress Io, generating heat that melts parts of its interior. However, the latest data indicates that the deformations aren’t extensive enough to support the idea of a global magma ocean.
“If Io had a global magma ocean, its tidal deformation signature would be far larger,” explains Scott Bolton, a space physicist from the Southwest Research Institute.
Io’s surface is a dramatic landscape, often described as resembling a “pizza,” with colorful deposits of silicates and sulfur dioxide. The moon’s lava flows and volcanic eruptions can stretch hundreds of kilometers, creating a constantly shifting and fiery terrain.
The discovery adds new layers to our understanding of tidal forces and their impact, which could have implications for other celestial bodies, such as Saturn’s Enceladus, Jupiter’s Europa, and even exoplanets.
“This research enhances our knowledge of tidal flexing and its effects, which are crucial for studying moons like Enceladus and Europa, as well as distant exoplanets,” says Ryan Park, astronautical engineer at NASA’s Jet Propulsion Laboratory.
As scientists continue to unravel Io’s mysteries, the findings could lead to a broader understanding of volcanic and tidal processes across the universe, opening new doors for planetary science and exploration.
