Jupiter

## Atmosphere

### **Composition**

-Hydrogen (89%)-Helium (10%)-Methane (0.3%)-Other elements (0.7%)

## General information

The biggest planet in the Solar System, Jupiter is located five planets from the Sun. It is a gas giant with a mass that is slightly less than one thousandth of the Sun's and more than 2.5 times that of all the other planets in the Solar System combined. Jupiter has an orbital period of 11.86 years and revolves around the Sun at a distance of 5.20 AU. Since ancient times, people have been observing Jupiter, the third brightest natural object in the Earth's night sky after the Moon and Venus. **Jupiter**, the main deity of classical Roman religion, inspired its name.

Since Jupiter was the first planet to form, a large portion of the other planets' formation histories were influenced by its inward migration throughout the early Solar System. Helium, which accounts for one-tenth of Jupiter's volume and a quarter of its mass, is the second most common element on the planet after hydrogen. More heat is produced by Jupiter's inner contraction than the planet gets from the Sun. Its interior structure is thought to consist of a diffuse inner core made of denser material and an outer mantle of liquid metallic hydrogen. Jupiter is a fast-rotating asteroid with a rotational speed of one revolution every ten hours. There are turbulence and storms along the interacting edges of a sequence of latitudinal bands that divide the outer atmosphere.

Jupiter has the second biggest continuous structure in the Solar System, a strong magnetosphere, and is encircled by a weak planetary ring system. Jupiter has a moon system that includes 95 known moons and most likely many more, including the four major moons—Io, Europa, Ganymede, and Callisto—that Galileo Galilei discovered in 1610. The largest of the four, Ganymede, is bigger than Mercury. Io and Europa are about the size of the Moon; Callisto is the second biggest.

Nine robotic missions have visited Jupiter since 1973: two orbiters and seven flybys, plus one orbiter that is now in route and one that is ready to launch.

### History

#### Formation

It is thought that Jupiter is the oldest planet in our solar system. According to current conceptions of the origin of the Solar System, Jupiter formed at or above the snow line, which is the distance from the early Sun at which it was cold enough for volatiles like water to condense into solids. The planet's gaseous atmosphere was first gathered around a solid core. Therefore, the planet had to develop before the solar nebula was completely scattered. Jupiter grew in mass throughout its development, reaching a mass twenty times that of Earth, with ices, silicates, and other heavy elements making up around half of its mass. The solar nebula developed a gap when the proto-Jupiter expanded to be larger than 50 Earth masses.

The "grand tack hypothesis" states that Jupiter formed at a distance of around 3.5 astronomical units from the Sun. The young planet migrated inward as it accreted mass due to interactions with the gas disk around the Sun and orbital resonances with Saturn. Several super-Earths circling closer to the Sun had their orbits disturbed by this, which led to catastrophic collisions between them. Later on, Saturn would have started to migrate inward as well—much more quickly than Jupiter—until the two planets were caught in a 3:2 mean motion resonance at a distance of around 1.5 astronomical units from the Sun. They moved away from the Sun and out of the inner system to their current places as a result of this altering the direction of migration.

### Properties

#### Great Red Spot

The Great Red Spot is a high pressure area on Jupiter that causes the largest thunderstorm in the solar system. The winds in this area are around 432 kilometers per hour, or 268 miles per hour. Observations have been found since the mid 1600s, which would make the storm over 358 years old. The storm has been decreasing 580 miles per year. While the color for the storm is not known, multiple theories suggest it is from ammonium hydrosulfide.

### Explorations

Multiple spacecrafts have travelled to or past Jupiter.

* Pioneer 10
* Pioneer 11
* Voyager 1
* Voyager 2
* Ulysses
* Cassini-Hyugens
* New Horizons
* Galileo
* Juno

#### Structure

The atmosphere at the surface of Jupiter is composed mainly of hydrogen, helium, and other gases. Hydrogen makes up between 88% to 92%, helium 8% to 12%, while the other gases are less than 1%.

The bottom part of the atmosphere is extremely hot, and the pressure is so high that helium is turned into a liquid. The liquid helium then rains down onto the planet.

The outer core of Jupiter is an ocean of liquid hydrogen. The pressure there however can turn the hydrogen into a solid. But because of temperatures, it melts down.

Jupiter has bands of clouds and gases moving on its outer atmosphere. These bands are divided into two types, named zones and belts. Zones are bands with lighter colors, while belts have darker colors. Zones and belts interact with each other. This creates conflicting air patterns, which can cause storms.

Jupiter, as well as the rest of the gas giants, has rings, however they are not as visible as Saturn’s. These rings were discovered in 1979 when Voyager 1 flew by the planet.

Jupiter's rings are separated into four sections. The first ring is the Halo Ring. The Main Ring is the second ring. The two final rings are Gossamer rings. They are not visible because they are made of microscopic dust.

Jupiter has a magnetic field 11 times stronger than the earth. Jupiter’s moons orbit the planet inside the magnetic field, which protects them from the solar wind. Jupiter also experiences auroras on its poles due to charged particles from the volcanic moon Io. Jupiter's magnetosphere reaches the orbit of Saturn, or 12 million kilometers.

#### Moons

* Europa
* Ganymede
* Io
* Callisto
* Amalthea
* Himalia
* Carme
* Valetudo
* Adastrea
* Thebe
* Pasiphae
* Ananke
* Elara
* Sinope
* Lysithea
* S/2003 J 2
* S/2003 J 12
* Calirrhoe
* Themisto
* Kalyke
* Eupheme
* Arche
* Cylenne
* Chaldene
* S/2003 J 4
* S/2003 J 9
* S/2003 J 10
* S/2003 J 16
* Eirene
* Eukelade
* Iocaste
* Hegemone
* Aoede
* Helike
* Harpalyke
* Herse
* Autonoe
* Erinome
* Jupiter LXI
* Philophrosyne
* Isonoe
* Hermippe
* Aitne
* Euporie
* Euanthe
* Eurydome
* Megaclite
* Metis
* Jupiter LXII
* Thyone