Io, Jupiter’s third-largest moon, is a place of extraordinary volcanic chaos, the Washington Post reports.
With its pepperoni-pizza-like appearance, dotted with numerous volcanic eruptions, it is the most volcanically active body in our solar system. Despite being slightly larger than Earth’s moon, Io is home to hundreds of volcanoes and lava lakes, releasing sulfur dioxide into the atmosphere and constantly altering its surface.
Scientists have long been intrigued by the origins of Io’s intense volcanic activity. Early theories suggested that a global magma ocean might be responsible, offering an explanation for the widespread eruptions. However, new data from NASA’s Juno spacecraft is shedding light on a different possibility. Research, published in Nature and presented at the American Geophysical Union conference, suggests that the volcanoes on Io are powered by individual magma channels, much like those on Earth.
The key to Io’s volcanic activity lies in its relationship with Jupiter, the largest planet in our solar system. As Io follows an elliptical orbit around Jupiter, the gravitational pull causes dramatic tidal forces that stretch and squeeze the moon’s surface. These intense forces can cause Io’s surface to bulge by up to 330 feet, generating significant heat through friction. This phenomenon, known as tidal flexing, causes Io’s interior to heat up, resulting in volcanic eruptions.
Scott Bolton, director at the Southwest Research Institute, explains that the immense size of Jupiter exerts such force on Io that it effectively “squeezes the insides out of the moon.” This tidal heating is comparable to the way squeezing a rubber ball generates warmth. While this mechanism is too extreme to make Io habitable for humans, it could play a key role in supporting life on other moons of Jupiter, such as Europa and Ganymede, which may have the potential to host life in more stable environments.
For years, scientists have speculated that Io’s volcanic activity could be linked to a global magma ocean beneath its surface, a feature that might have been common in the early solar system. However, Juno’s recent observations show that this is not the case. Rather than a global liquid layer, Io’s volcanic activity is driven by smaller, localized magma channels, similar to those found on Earth. This finding challenges previous assumptions about the early evolution of planetary bodies and suggests that a global magma ocean was not necessary for widespread volcanic activity in the solar system.
By studying the deformation of Io’s surface, scientists were able to rule out the presence of a global magma ocean. Instead, the data indicates that magma rises through channels like capillaries, eventually reaching the surface to fuel the moon’s hundreds of volcanoes. This new understanding could impact how researchers view the formation of other planetary bodies and the early evolution of the solar system.
Although the mystery of Io’s volcanic origins remains unsolved, researchers are now exploring other possible contributing factors. For example, NASA’s Heidi Becker has found evidence suggesting that tectonic activity could also play a role in the formation of mountains and volcanoes on Io’s surface.
