The huge orange-red Jupiter is the largest gaseous planet in the solar system. The ancient Romans gave her a name quite appropriate: Jupiter (among the ancient Greeks Zeus) was the supreme god on Olympus. He has a huge number of large and small companions, who are named according to the names of many lovers, wives and descendants of the aforementioned god.
The largest moons of Jupiter are Ganymede, Europe, Io and Callisto. They are also called Galilean satellites, since the famous Galileo Galilei was the first to notice them in the sky in the winter of 1610. To do this, he needed a telescope, increasing the size by 32 times.
Like Jupiter itself, its satellites are very bright, and their orbits are far from each other, so they are easy to see even with modern field binoculars.
Eight interplanetary stations sequentially explored the planet and its satellites. Based on these studies, we can confidently say that all the moons of Jupiter are very unusual and each of them has its own “highlight”.
Io is the most colorful satellite. This is explained by the fact that it has many actively active volcanoes that spew black, red, yellow, brown, orange lava. On no other celestial bodies entering the solar system, besides the Earth, there are no more active volcanoes. Therefore, Io bears the title of the most volcanically active planet. And in the ionosphere of this satellite, under the influence of the magnetic field of Jupiter, high-intensity auroras continuously flash.
Another satellite of Jupiter, Europe is the lightest and smoothest solid heaven in the solar system. The elevations on its surface do not exceed one meter in height. Craters from asteroids are also shallow and almost invisible. The explanation for this phenomenon is that the entire planet is covered with a thick layer of ice, under which scientists suggest the presence of a huge salty ocean. When cracks and faults form on the surface of Europe, water enters there and freezes immediately, filling in the bumps. Moreover, in the waters of the “icy” ocean there may be primitive life. True, everything is complicated by a very high level of radiation on the planet. But scientists expect to solve all scientific and technical problems and with the help of probes carefully explore this mysterious satellite of Jupiter.
The largest of all satellites is Ganymede. In size, it exceeds Mercury, and it could well have been an independent planet of the solar system if it had not rotated around Jupiter, but around the Sun. Ganymede is covered with a layer of ice, and its thickness is much more significant than in Europe. The entire surface of the satellite is streaked with smooth furrows, the width of which reaches 15 km and a length of 30 km. Another interesting feature of Ganymede is the presence of active “volcanoes” that spew out salt-water solution rather than lava. From atmospheric phenomena, astronomers have discovered the loss of hoarfrost, the composition of which has not yet been studied.
Callisto is the farthest and oldest satellite of Jupiter. It also consists mainly of ice, water and minerals, and its entire surface is covered with craters of various diameters. This celestial body does not have a magnetic field, which means that there is no solid metal core.
In addition to four large ones, there are also smaller satellites of Jupiter - there are about sixty of them. These are blocks of stone and asteroids removed from Jupiter that fell into its gravitational field, such as Karma and Sinope. There are also the so-called internal moons of Jupiter, whose orbits pass inside the orbit of Io. On the surface of these satellites, the largest of which are called Amalthea and Adrastea, volcanic emissions of Io settle.