Great Balls of Gas: Jupiter and Saturn

Journeying Inside Jupiter and Saturn

• Telescopic images of Jupiter and Saturn reveal clouds that are composed of ammonia ice, water ice, and a substance known as ammonium hydrosulfide. These trace substances are used to create cloud materials.
• Similar to the Sun, Jupiter and Saturn primarily consist of hydrogen and helium.
• The Great Red Spot (GRS) on Jupiter and the other off-white tints in the clouds of the two large planets are mysteries to scientists.
• Jupiter is 318 times as massive as Earth, while Saturn is about 95 times more massive.
• Infrared light illuminates Jupiter and Saturn intensely, giving off nearly as much energy as the Sun does.

Gazing at Jupiter

• Jupiter is sometimes called by scientists “the star that failed.”
• Jupiter's diameter is approximately 88,700 miles or 11 times greater than that of Earth.
• The gas giant rotates extremely quickly, completing a full rotation in just 9 hours, 55 minutes, and 30 seconds.
• Belts: Jupiter’s darker bands of clouds.
• Zones: Jupiter’s lighter bands of clouds.
• Jupiter appears as a circular disk through a telescope.
• The North and South Equatorial Belts flank the Equatorial Zone, which runs straight down the middle of the disk.
• Great Red Spot: A storm in the South Equatorial Belt that at times has been as big as Earth and sometimes bigger.
  • Infrared observations reveal that the atmosphere above the Great Red Spot is significantly warmer than any other place.
• The magnetosphere of Jupiter is made up of energetic subatomic particles, similar to the magnetosphere of Saturn.
• Saturn's rings are bright because they are mostly ice, in contrast to Jupiter's dark rings, which are composed of microscopic rock particles.
• Any object that passes through the Jovian magnetosphere receives a strong radiation dose.

Four Basic Details about the Galilean Moons

• Callisto
  • Its surface is dark and covered in numerous white craters.
  • The surface is probably dirty ice — a mixture of ice and rock.
  • White craters are the result of large meteoroids, asteroids, and comet impacts that exposed the clean ice beneath.
  • Valhalla: The most noticeable marking; is a huge-ringed impact basin.
• Europa
  • The surface of this moon is ridged and resembles ice rafts.
  • An underground ocean that is possibly 60 miles deep is covered by a frozen crust that is about 10 miles thick.
  • It is one of only six locations outside of Earth where there is a strong case for subsurface liquid water, according to scientists.
• Ganymede
  • It is the largest moon in the solar system, measuring 3,270 miles in diameter.
  • Light and dark terrains, possibly ice and rock, are scattered across its splotchy surface.
• Io
  • There are more than 400 volcanoes scattered across the surface of this moon.
  • It has no visible impact crater because all impact sites have been covered up by lava from the numerous volcanoes.

Setting Saturn

• Saturn, with a diameter of approximately 75,000 miles, is the second-largest planet in our solar system.
• Many people believe that Saturn is the most beautiful planet.
• Cassini Division: A gap in Saturn’s rings.
• Saturn is even more oblate than Jupiter and spins once every 10 hours, 32 minutes, and 45 seconds. Its poles are also flattened.
• The rings maintain a fixed orientation, pointing face-on in one direction in space, and are very large but also very thin.
• As Saturn travels around its own 30-year orbit, the rings are sometimes edge-on and appear to vanish through small telescopes.
• A large white cloud, also known as a "great white storm," can be seen in Saturn's northern hemisphere about once every 20 to 30 years.
• The cloud is dispersed by swift winds until it encircles the entire planet in a thick, bright band.
• Titan: Saturn’s largest moon.
  • The dunes in Titan are aeolian — the wind shapes them or forms them, like Earth’s sand dunes in deserts or at the beach.
• Cryovolcanism: The eruption of ice-cold material.