Imagine a moon with the size and very close composition of our Moon, but whose surface looks like a melted Pizza. Imagine a moon orbiting so far from your planet as the Moon is from Earth, but turning around this planet not in 28 days as our satellite, but in 1.7 days. Welcome to Io, the innermost of the four Galilean Moons giants.

As our moon, Io has a face always turned to his planet.

If you could stay in this face and look up, you would have seen that!

Jupiter and its rings of multicolored clouds and turbulenyas occupy almost a quarter of the sky. Jupiter is all in the life of this moon. He dominates like no other planet dominates a satellite. It is an area that has extraordinary and drastic consequences for the Moon Pizza.

On March 8, 1979, Voyager 1, flying faster than a speeding bullet, passed quickly by the Jupiter system and headed for Saturn. Before the probe leave forever the Jovian system she turned back and took a partial picture of Io.

When the navigation engineer Linda Morabito studied the image, his heart raced. A phosphorescent gas cloud was gushing from the small Crescent Moon.

Morabito discovered the super volcanoes of Io. In the following days the team found a total of 8 giant clouds casting material hundreds of miles in space.

It turns out that Io is the body more geological activity in the solar system, with more than 400 active volcanoes. Its surface Pizza, orange, yellow and brown is full of vents as if geysers.

In fact that is what they are instead of volcanoes. The lava of molten interior, rather than erupt daily, overheat the liquid sulfur dioxide just below the surface that escapes through vents as water vapor escapes from a terrestrial geyser.

Io expels billion tons of matter in space every year. As matter falls back under the weak gravity, it covers the surface with sulfur. The colors of pizza Moon are just the colors that sulfur has at different temperatures.

But what moves the supervolcanoes Io?

If you continuously heating a rubber ball inside it was warm. This is what Jupiter's gravity causes Io. Giant's attraction is greater in the side planeeta than the opposite, so the moon is stretched. And, like a piece of toffeee if stretched in one direction, there is a compression compensation perpendicular direction.

Io orbits the same distance as the Moon orbits the Earth. But Jupiter's mass is almost 2600 times that of Earth. Therefore, tidal forces, which stretch and squeeze Io is approximately 2600 times greater than those exercised by the earth on the moon.

In fact it is worse than that. For each orbit around Io complete Jíupiter, Europe completes two and Ganymede, one. The existence of this orbital resonance implies periodic alignments of satellites in which Io is pulled in one direction by the moons and the other by Jupiter. In the middle of this tug of war is not surprising that the interior of Io, taking into account the volume difference, has more heat than the sun.

Source: Solar System, Mark Chown

Adaptation: Avani Soares