Jupiter
The King of Planets
Jupiter is the largest planet in our solar system, with a mass more than twice that of all other planets combined. This gas giant is known for its Great Red Spot, a storm larger than Earth that has raged for centuries.
Key Facts About Jupiter
- Diameter: 139,820 km (86,881 miles)
- Distance from Sun: 778.5 million km (483.8 million miles)
- Day length: 9.9 hours
- Year length: 11.9 Earth years
- Known Moons: 95
- Rings: Faint ring system
The Great Red Spot
Jupiter's Great Red Spot is a massive anticyclonic storm that has been observed for at least 350 years. It is large enough to contain Earth and has winds reaching up to 640 km/h (400 mph).
Galilean Moons
Jupiter's four largest moons — Io, Europa, Ganymede, and Callisto — were discovered by Galileo Galilei in 1610. Europa is of particular interest because it may have a subsurface ocean that could support life.