It has a thin atmosphere and consists of two moons revolving around it, Phobos and Deimos. Jupiter. It was discovered in 1892 by Edward Emerson Barnard. More › Critical Science Targets Io is the most volcanically active body in the solar system. 5. Their semi-major axes range between 128,000 and 222,000 km.. Discovered: 1892; Diameter: 167 km; Orbital Period: 11 hours 57 minutes; Mass: 208 × 10 16 kg; Surface Temperature: 120K; Surface Gravity: 0.020 m/s 2; 4] Thebe. The planet Jupiter's four largest moons are called the Galilean satellites after Italian astronomer Galileo Galilei, who first observed them in 1610. NASA observes that main group (Galilean Moons) consists of some of the largest bodies in the solar system besides the sun and planets. The inner satellites (the Amalthea Group) orbit nearest to Jupiter and are responsible for replenishing and maintaining Jupiter’s ring system. The German astronomer Simon Marius claimed to have seen the moons around the same time, but he did not publish his observations and so Galileo is given the credit for their discovery. Amalthea is the third closest moon to Jupiter and was the fifth moon of the Jupiter to be discovered. Europa (Jupiter II), the second of the four Galilean moons, is the second closest to Jupiter and the smallest at 3121.6 kilometers in ... Callisto has long been considered the most suitable place for a human base for future exploration of the Jupiter system since it is furthest from the intense radiation of Jupiter. The inner moons of Jupiter are four small moons that orbit close to Jupiter.These moons are closely interconnected with the rings of Jupiter and serve as both sources and sinks of the ring's material. Located at a distance of 778 million km or 5.2 AU, it is two and half times larger than all other planets of the solar system combined. A List of Jupiter's Moons Here is a list of all the named moons of Jupiter. From nearest to Jupiter to farthest, the four Galilean moons are: Io , a red-orange sulphuric hell-hole of a world, where volcanos spray molten lava high into space. Although the planet has 39 moons that we know about, not all of them have names yet. There are many interesting moons orbiting the planet, but the ones of most scientific interest are the first four moons discovered beyond Earth—the Galilean satellites. Amalthea is named after a naiad who nursed the newborn Jupiter (Zeus). Combined, scientists now think Jupiter has 79 moons. This list is just the ones that are "lucky" enough to have been named. Examples of … On the other hand, there are two sub-groups of irregular satellites namely prograde and retrograde. Io shouldn’t have a molten core– it’s too small– but the gravitational push and pull of Jupiter kneads the core of this small world, and keeps it perpetually active. The 5th planet from the Sun and the most massive one, Jupiter is 317 times the mass of Earth. Jupiter has 53 named moons and another 26 awaiting official names. They are in order from the closest to the furthest away from Jupiter.