Jupiter

Jupiter weighs three times more than all the other planets combined. Its great mass causes it to act like an enormous cosmic vacuum cleaner. Its gravitational influence attracted much of the debris in the early solar system. Without this thinning effect on the asteroid population the Earth would have suffered a much more severe bombardment from space during its history. Repeated catastrophic impacts would have almost certainly prevented the evolution of intelligent life. Without Jupiter guarding over us, we wouldn’t exist!

The toxic atmosphere of Jupiter, formed from hydrogen, ammonia and methane, is whipped into a raging broth of cyclones and storms by the planet’s rapid spin rate (just ten hours). The light and dark bands of colour are wrenched in opposite directions, resulting in continent-sized turbulent regions that can be stable for many centuries. The most famous feature, the Great Red Spot, is probably created as darker molecules from inside the planet are churned up to the surface by the violent storms.

Jupiter’s rapid spin rate combined with its core of metallic hydrogen gives the planet an extremely strong magnetic field. This interacts with the Solar Wind to produce the largest enduring structure in the solar system. Jupiter’s magnetic cocoon stretches almost a billion kilometres, spanning the distance between the orbits of Jupiter and Saturn. A combination of the strong magnetic field and charged particles from the Sun results in currents as high as 5 million amps flowing between Jupiter and one of Jupiter’s satellites, Io. This natural power station generates a power of 2.5 trillion watts, vastly exceeding the energy we can produce on Earth.

Everyone is familiar with the majestic rings that encircle the planet Saturn, but it is not the only planet in our solar system that is surrounded by a disk of material. In 1977 astronomers were surprised to find faint and narrow rings surrounding the planet Uranus, and in 1979 Voyager 1 photographed a faint ring around the planet Jupiter. Shown in the image to the right, Jupiter’s rings are made from extremely small particles comparable in size to the particles in cigarette smoke. These objects are constantly falling into Jupiter’s upper atmosphere and being replenished by dust that is sandblasted off Jupiter’s two innermost moons by meteorites.