Jupiter's Moon Research Paper

Jupiter’s Moons: The Galilean Satellites

When you think of Jupiter what comes to your mind? Perhaps it’s impressive size, otherworldly glow and stripes, it’s Great Red Spot? What about it’s satellites? Most of Jupiter’s greatest secrets lie in its vast amount of moons reaching a total of 67 so far-53 named and 14 that have not yet been given a name or status. Jupiter’s largest and most scientifically interesting satellites are known as the Galilean Satellites for Galileo Galilei. In order of distance from their planet: Io, Europa, Ganymede, and Callisto. These were the first four moons discovered other than our own and are some of the most sought after, active, and fascinating moons in our entire solar system. The four satellites Io, Europa, Ganymede and Callisto are very
large and all but Europa are larger than our Moon. Galileo Galilei first spotted these four bodies orbiting around Jupiter with his telescope in 1601; they are referred to as The Galilean Satellites after their discoverer. He saw two stars in a line around Jupiter and noticed after a few days that they followed it through the sky. They orbit close to Jupiter’s equatorial plain in a flattened disk that resembles a mini solar system. They were possibly even formed in a similar, scaled-down way as our solar system. Some astronomers believe Jupiter heated the orbiting debris, which affected the composition of the moons. Causing the inner most moons ice to evaporate and have a more rocky composition than their outer, icier neighbors. The bodies’ strange, often colorful surface features could have also originated from the heating. It also caused the inner, rockier moon’s densities to be higher than the outer icy moons and they increase with distance. Starting with Io, the closest moon orbiting Jupiter, (in units of grams per cubic centimeter) 3.53, Europa 2.99, Ganymede 1.94 and Callisto the furthest one is 1.85. Galileo’s discovery created earth-shattering news to the people back then, stating the idea that world is not geocentric with the Earth being the center of the universe. One of the first discovered and closest Galilean Satellites to Jupiter is the moon named Io.
Io is Jupiter’s most dense, third largest moon and is slightly larger than our moon. It has a colorful surface that is possibly caused by sulfur from volcanoes and is actually the most volcanically active body in the solar system. Hundreds of Volcanic plumes rise 300 kilometers above the surface. What is causing Io to be so active? It travels in an irregular elliptical motion thanks to Europa, Ganymede and Jupiter’s strong gravity. This causes tides in Io’s surface that rise up to 100 meters which generates enough heat for the volcanic activity and eliminates any water that could have existed. The immense pressure from the inside of Io caused by the tides of its neighboring satellites keeps it’s crust in a liquid state and causes the volcanoes and in turn renews it’s surface and is why its surface appears to be so young to astronomers. Io’s orbit around Jupiter actually cuts through Jupiter’s intense magnetic lines, which causes Io to be an electric generator, this and other forces create lightning in the planets upper atmosphere. The second and other first discovered Galilean Satellite is
Europa. Europa is the smallest of all the Galilean moons and is the only one that is not larger than our own moon. Europa is possibly one of the most intriguing bodies in our solar system other than Earth. Its surface is bright, smooth with reddish long lines -called linear fractures- scoring it and consists of mostly water ice and the reddish color comes from an unknown material. Similar to Earth, the moon is thought to have an iron core, rocky mantel and a saltwater ocean below its icy crust. This ocean would be deep enough to extend all the way from its iron core to its surface! Europa orbits Jupiter every three and a half days and is locked by gravity to Jupiter and the same hemisphere always faces the planet. Its orbit is also a slightly stretched out elliptical and its distance from Jupiter varies which creates tides that stretch and relax its surface. The tides occur from Jupiter’s stronger gravity pull on the near side of the moon than on its far side. This stretching creates the linear fractures on Io’s surface and if its ocean does exist it might also create hydrothermal activity on the seafloor, supplying nutrients that could make the ocean suitable for living things, could be the recipe for life (NASA). And that reddish unknown material could also possibly be a clue into the moons potential of being a habitable world!