Jupiter

The largest planet in the Solar System is Jupiter, a gas giant that is 2.5 times heavier than all the other planets put together. This dominant planet almost has its own minor solar system, being orbited by over 60 moons, some of which are as large as Mercury.

Pioneer 10 and 11 were the first probes to reach the planet and take close-up pictures in 1973 and 1974 as they flew past. Jupiter has a band structure parallel to its equator, these bands being stable cloud formations. As a ball of gas, the planet rotates very quickly, and the weather on Jupiter is quite turbulent. A striking feature on the planet is the large red spot, a huge whirlwind that has been raging in Jupiter's atmosphere at least since its discovery centuries ago.

The four most prominent moons of Jupiter can be discerned as small dots using binoculars. Io, Europa, Ganymede and Callisto are also known as the Galilean moons, having been named after their discoverer, Galileo Galilei. Most of the other moons are very small. The majority of these are presumably asteroids that were captured by Jupiter.

Jupiter is a flying test laboratory for solutions to the so-called restricted three-body problem. This consists of predicting the trajectory of three bodies that are all attracted to each other by gravity. What sounds simple is actually a mathematically unsolvable problem. However, if the mass of one of the three objects is negligibly small compared to the other two, 5 positions can be determined in which the smallest body can rest stably. These positions are known as Lagrange points L1 to L5 after the mathematician Joseph-Louis Lagrange.

Jupiter is so massive that, together with the Sun, it can be regarded as an isolated system with all other celestial bodies being simply neglected. If one now looks at the Lagrange points of Jupiter, one can actually discover stable, stationary objects there. Particularly prominent are two asteroid groups, the Trojans, which are located in the Lagrange points L4 and L5 of Jupiter.