outer planets

rotation of the four outer planets

All four planets rotate relatively rapidly, which causes *wind* patterns to break up into east-west bands or stripes. These bands are prominent on Jupiter, muted on Saturn and Neptune, and barely detectable on Uranus.

Jupiter

As of 2004, Jupiter is thought to have the most moons, with more than sixty.

outer planets

Finally, all four are accompanied by elaborate systems of *rings* and *moons*.

gas giants

However, gas giants may have a rocky or metallic core—in fact, such a core is thought to be required for a gas giant to form—but the majority of its mass is in the form of *gas* (or gas compressed into a liquid state), mainly *hydrogen* and *helium*. Unlike rocky planets, which have a clearly defined difference between atmosphere and surface, gas giants do not have a well-defined surface; their atmospheres simply become *denser* toward the core.

Jupiter 2

JUPITER Jupiter is the fourth *brightness* object in the sky (after the Sun, the Moon and Venus). Jupiter is about *75*% hydrogen and *25*% helium (by mass) with traces of methane, water, ammonia and "rock". This is very close to the composition of the primordial Solar *nebula* from which the entire solar system was formed. Jupiter probably has a core of *rocky* material amounting to something like 10 to 15 Earth-masses. Size Jupiter is approximately *11* times the size of Earth. Jupiter is huge and look like a dot to it which is earth(looks like a dot). Day/Year Jupiter's day is *10* Earth hours long and its year *12* Earth years long. Atmosphere Jupiter has high velocity *winds* which are confined in wide bands of latitude. The winds blow in *opposite* directions in adjacent bands. Slight chemical and temperature differences between these bands are responsible for the colored bands that dominate the planet's appearance. Where ever the different colors are will be blowing in the opposite direction. Temperatures Jupiter radiates more *energy* into space than it receives from the Sun. The interior of Jupiter is hot: the *core* is probably about 20,000° C. The surface has an average temperature of -150° C. Great Red Spot The Great Red Spot has been seen by Earthly observers for more than *300* years. It is an oval-shaped *storm*, about 7,000 by 15,000 miles, and big enough to hold two Earths. Moons Jupiter has *79* known satellites (as of 2018): the four large Galilean moons plus many more small ones, some of which have not yet been named. Jupiter is very gradually *slowing* *down* due to the tidal drag produced by the Galilean satellites. Also, the same tidal forces are changing the orbits of the moons, very slowly forcing them farther from Jupiter. Ganymede is the *largest* moon in the Solar System. Rings Jupiter has rings like Saturn's, but much *fainter* and smaller. Unlike Saturn's, Jupiter's rings are dark, and are probably composed of very small grains of rocky material. Also unlike Saturn's rings, they seem to contain no ice. All of the outer planets have rings and the inner planets do not have rings.know this.

4 gas giants

Jupiter,Saturn, Uranus and Neptune

Neptune

NEPTUNE Neptune cannot be seen using the *eyes* alone. Neptune was the first planet whose existence was predicted *mathematically* (the planet Uranus's orbit was disturbed by an unknown object, which turned out to be another gas giant, Neptune). Occasionally, Neptune's orbit is actually outside that of *pluto*; this is because of Pluto's highly eccentric (non-circular) orbit. During this time (20 years out of every 248 Earth years), Neptune is actually the farthest planet from the Sun (and not Pluto). Size Neptune is just under *4* times the size of Earth. Day/Year Neptune's day is *19* Earth hours long and its year *165* Earth years long. Since Neptune was discovered in 1846, it has not yet completed a single *revolution* around the sun. Atmosphere Like a typical gas planet, Neptune has rapid *winds* confined to bands of latitude and large storms or vortices. Neptune's winds are the *fastest* in the solar system, reaching 1,200 mph. Temperatures Like Jupiter and Saturn, Neptune has an *internal* heat source -- it radiates more than twice as much energy as it receives from the Sun. It has an average surface temperature of -225° C. Neptune's rotational axis is tilted 30 degrees to the plane of its orbit around the Sun (this is few degrees more than the *earth*). This gives Neptune seasons. Each season lasts *40* years; the poles are in constant darkness or sunlight for 40 years at a time. Moons Neptune has *13* moons. Rings Neptune has narrow *faint* rings arranged in clumps.

Saturn

SATURN Saturn is the least *denser* of the planets; its specific gravity (0.7) is less than that of water. Saturn's shape is known as an oblate spheroid--it is *flattened* at the poles and bulging at the *equator*. Size Saturn is approximately *9* times the size of Earth. Day/Year Saturn's day is *10* Earth hours long and its year *30* Earth years long. Temperatures Saturn's interior is *hot* (12,000° C at the core) and Saturn radiates more energy into space than it receives from the *sun*. The surface has an average temperature of -185° C. Moons Saturn has *62* moons (as of August, 2018), 53 of which are named moons. *Titan* is the second largest moon in the solar system. Rings Saturn's rings are only visible from Earth using a telescope. They were first observed by *Galileo*. They are made of *ice* chunks (and some rocks) that range in size from the size of a fingernail to the size of a car. Although the rings are extremely wide (almost 185,000 miles in diameter), they are very thin (about 0.6 mile thick). Despite their impressive appearance, there's really very little *material* in the rings -- if the rings were compressed into a single body it would be no more than 100 km across.

Saturn

Saturn's rings are the most spectacular, and were the only ones known before the 1970's.

Jovian Planets

The gas giants (sometimes also known as a Jovian planet after the planet Jupiter) are large planets that are not primarily composed of *rock* or other solid matter.

Uranus

URANUS Uranus is a huge, *gas* planet that is covered with clouds. Its blue-green color is caused by the methane (CH4) in its atmosphere. Uranus' rotational axis is strongly *tilted* on its side (97.9°). Instead of rotating with its axis roughly perpendicular to the plane of its orbit (like all the other planets in our Solar System), Uranus rotates on its *side* (along its orbital path). This tipped rotational axis gives rise to extreme *seasons* on Uranus. It appears that Uranus does not have a *rocky* core like Jupiter and Saturn but rather that its material is more or less uniformly distributed. Size Uranus is approximately *4* times the size of Earth. Day/Year Uranus' day is *18* Earth hours long and its year *84* Earth years long. Temperatures Uranus radiates very little *heat* in comparison with the other gas giants. The surface has an average temperature of -212° C. Atmosphere Uranus is a *frozen*, gaseous planet with a molten core. Uranus' atmosphere consists of 83% hydrogen, 15% helium and 2% methane. Moons Uranus has *5* large moons and many smaller moons; 21 moons have been named. They have the ability to pull in and grab moons. Rings Uranus has a belt of *11* faint, narrow rings composed of rock and dust. They circle Uranus in very elliptical orbits. These rings are only a fraction of the size of Saturn's rings, and were only discovered in 1977.

Moons

ex:IO, Europa, Ganymede, Callisto which are moons, the most known.