Io’s long-debated magma ocean may not exist. 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 ...

NASA's Voyager 1 spacecraft discovered active volcanoes on Jupiter's moon Io. Before Voyager 1 flew by Io, scientists believed the moon to be a dead world much like Earth's moon. The mission ...