Jupiter 's moons have always been a slight mystery to the people of Earth; lately it has become an even bigger topic of interest. Ever since we sent a probe to Jupiter and it explored the moons, Io and Europa. Both of these moons have possible means for life.
These two moons were discovered on January 10, 1610 by Galileo Galilei. One night when he was star gazing, he looked at Jupiter and saw four little stars around it. These little stars turned out to orbit Jupiter, therefore they are moons. These four moons were: Io, Europa, Ganymede, and Callisto. These four moons are now known as the four Galilean satellites.
Io is a volcanically active moon. It is extremely cratered and looks something like a melted cheese pizza. Io is actually the most volcanically active moon in our solar system to our knowledge. Io has volcanic plumes up to 190 miles above the surface. Io is a tad larger than Earth 's moon and Jupiter 's third largest. Io has a very elliptical, irregular orbit due to Europa and Ganymede disturbing it. Due to this irregular orbit Io has ridiculous tidal forces that cause Io 's surface to bulge in and out by as much as 330 feet. If someone were to compare these tidal forces to those which we have on Earth, the person would see that the place where earth 's highest tide is only 60 feet. Then they have to remember that that is only in water, Io 's tidal forces can happen on solid ground.
These tidal forces produce amazing amounts of heat on Io. These extreme temperatures cause most of Io 's sub crust surface to be predominantly liquid-like. The surface is like this, because it is searching for any possible escape route to relieve some of the atmospheric pressure. Also, with the surface as liquid-like as it is, its surface is constantly refilling all impact craters with molten lava. This lava 's contents are not exactly discovered yet, but scientists are led to the belief that it contains sulfur
Cited: Hunt, G., & Moore, P. (1981). Moons. In Jupiter (pp. 58- 69). New York, Chicago, San Francisco: Mitchell Beazley Publishers.