Jupiter

Fifth major planet from the Sun and the largest of the giant planets, one of the brightest objects in the Solar System.

DATA

Diameter: 142,800km (88,700miles)
Mass: (Earth=1) 317.9
Volume: (Earth=1) 1319
Density: (water=1) 1.33
Orbital Period: 11.86 Earth years
Rotation Period: 9 Earth hours, 50 mins, 30 seconds
Av. Surface Temp: -150°C (-238°F)

The Planet Jupiter

Viewed from Earth with a standard telescope, Jupiter’s elliptical yellowish disk is seen to be crossed by brownish-red bands, known as belts and zones. The most prominent feature is a great red spot (GRS); spots, streaks and bands are all caused by Jupiter’s rapid rotation and turbulent atmosphere. Eddies bring about the spots, which are cyclones, and anti-cyclones in the case of the GRS. Jupiter’s atmosphere is almost 90% hydrogen and the rest is mostly helium. The pressure at the top of the clouds is around 0.5 bar. At 1000km (600 miles) below the cloud tops there is an ocean of molecular hydrogen. At a depth of 20,000-25,000km (12,500 – 15,000 miles), under a pressure of 3 million bars, the hydrogen is compressed so that it behaves like a metal.

It is thought by Earth scientists that the middle of Jupiter is made from a massive iron-silicate core surrounded by an ice mantle. The core temperature is estimated at around 30,000k. The deep, metallic hydrogen mantle gives Jupiter a very powerful magnetic field. It traps a huge amount of plasma (charged particles); high-energy plasma is funnelled into radiation belts. Jupiter’s magnetosphere is huge, several times the size of the local sun, and causes powerful radio emissions. Jupiter has 16 major satellites.