Science, Maths & Technology
Other Moons
...source that powers Io’s activity is not radioactive, as for the Earth and (in the past) the Moon, but tidal. Tidal interactions between Io and the next two moons outwards, Europa and Ganymede, which take respectively twice and four times as long to complete one orbit, stoke enough heat into Io’s interior to melt the magma bodies that continually rise towards the...