What exactly do we know about Jupiter apart from its massive size and four planet-sized moons? We do know quite a bit about our solar system's largest planet, but it still remains a massive mystery which is why NASA has sent multiple missions, the most recent of which are Juno's exploration of the planet's surface and a further exploration of Europa, one of its four large satellites.
Did you know that Jupiter has rings? If you didn't, then here are some other things you may want to know about the largest planet in our solar system.
You may or may not have known that Jupiter was named after the king of Roman gods. Jupiter is the fifth planet from the sun at approximately 484 million miles away from it. A year in Jupiter is equal to about 12 Earth years and a single day at about 9.9 Earth hours, which is the shortest day in the solar system.
The gas giant is surrounded by 53 confirmed satellites, including four that are planet sized, and 14 other provisional ones. Compared to Earth, its gravitational pull is about 2.5 times greater and its width is about 11 times wider. Jupiter is so massive and its composition is so gaseous that if it had been approximately 80 times greater in size, it could have been classified as a star rather than a planet.
Astronomer Galileo Galilei was astonished when, in 1610, he discovered four small "stars" surrounding the planet. As it turns out, these "stars" were not stars but were, in fact, four planet-sized satellites surrounding the massive planet. Astronomers have since discovered about 67 moons, but Io, Europa, Ganymede, and Callisto remain to be its largest and most largely known moons.
Io is Jupiter's volcanic moon, and it is known as the most volcanically active body in the solar system. Callisto seems to bear remnants of when the solar system was created with its many craters, while Ganymede is well known for being the largest moon in the solar system as well as being the only moon to have its own internally generated magnetic field. Europa's icy surface is mostly water ice, and astronomers believe that it has twice as much water as the Earth.
Jupiter Has Rings?
When you think of a planet with rings, it's likely that the first planet you think of is Saturn, but did you know that Jupiter has rings too? They are difficult to see because they are made of small, dark particles. They were discovered in 1979 when NASA's Voyager 1 flew close to the planet.
Apart from 1979's Voyager 1 mission where NASA discovered the rings, Jupiter has also been probed by the Galileo spacecraft in 1995 and most recently, by the Juno spacecraft that was launched in 2011. So far, Juno's previous engine problem has led NASA to forgo shorter orbits around the planet, but they remain optimistic that the spacecraft will lead to more details and discoveries.