Image: In this photograph at the bottom left we see Ganymede passing in front of the gaseous monster, Jupiter.
Jupiter is a gas giant planet, the largest in the solar system.
• Size and mass: Jupiter has a mass of approximately 1.898 x 10^27 kg, which is approximately 318 times that of Earth. Its size is also impressive, with a diameter of 139,822 km, or about 11 times that of Earth.
• Atmosphere: Jupiter has a thick atmosphere composed mainly of hydrogen (about 89%) and helium (about 10%). There are also traces of methane, ammonia and water in Jupiter's atmosphere. Winds on Jupiter can reach speeds of up to 620 km/h.
• Great Red Spot: Jupiter is known for its Great Red Spot, a gigantic storm that has been circling Jupiter's atmosphere for at least 350 years. The spot is about three times the size of Earth and can be observed with a te
• Magnetosphere: Jupiter has a very strong magnetic field, about 20,000 times stronger than Earth's. This magnetic field is responsible for forming an extended magnetosphere around Jupiter, which shields the planet from charged particles in the solar wind.
• Satellites: Jupiter has at least 79 known natural satellites, the four largest of which are Io, Europa, Ganymede and Callisto. Ganymede is the largest satellite in the solar system.
• Rings: Jupiter also has a ring system, consisting of four main rings and several smaller rings. Jupiter's rings are made up of dust and small debris.
• Rotation: Jupiter rotates rapidly, with a rotation period of only 9 hours and 56 minutes.
• Orbit: Jupiter orbits the Sun at an average distance of about 778 million km, or about 5.2 astronomical units.
• Zones and belts: Jupiter's atmosphere is divided into light and dark colored bands, called "zones" and "belts". Zones are bright gas bands while belts are dark gas bands.
• Internal Composition: Jupiter's internal composition is mostly hydrogen and helium, but the pressure and temperature inside the planet are high enough for these gases to be compressed into a liquid metallic form.
The structure of Jupiter is not well known, but the gas giants were probably formed by accretion of hydrogen and helium gas, around a core of rock and ice. Learn more.
Definition of the word planet (August 24, 2006):
"A planet is a celestial body which is in orbit around the Sun, which has sufficient mass so that its gravity overcomes the cohesive forces of the solid body and maintains it in hydrostatic equilibrium (spherical shape), and which has eliminated any body moving in a near orbit".