The Solar System Lesson 6 Jupiter and Saturn Final Review The Solar System Lesson 6 Jupiter and Saturn

Compared to terrestrial planets, Jovian planets have Liquid metallic hydrogen centers Ring systems Emit more energy than they absorb from the Sun Have deep atmospheric zone and belt circulation

Jupiter does not have a true solid surface or continental plates.

Jupiter’s liquid metallic hydrogen is a characteristic of the planet not any of its moons. It is found at the planet’s core and conducts electricity.

The rocky material of Jupiter’s core is different from that on Earth in that it is much hotter and denser due to extreme pressure.

Jupiter’s interior is mostly hydrogen

Europa, one of Jupiter’s moons, has water oceans so any crater is quickly erased from its surface

The surfaces of Jupiter’s many old icy satellites are dark in color and have many craters.

Io and Europa are the two Galilean satellites of Jupiter which are geologically active.

Io is the only Galilean moon of Jupiter whose face is always facing Jupiter. This is due to the severe tidal forces acting on Io.

Satellites of Jupiter which lack craters are generally active bodies with new surfaces.

Some of Jupiter’s smaller moons are thought to be captured asteroids Some of Jupiter’s smaller moons are thought to be captured asteroids. They often have retrograde orbits.

Most of the particles of Jupiter’s rings are composed of silicate particles not of reflective ice.

Jupiter radiates about twice as much energy as it absorbs from the Sun This excess heat is due to the planet’s slow gravitational contraction. If Jupiter where about 80 times more massive it could become a star.

Due to Jupiter’s fast rotation and liquid metallic hydrogen core, it has a strong magnetic field and large magnetosphere. This intense magnetic field traps high energy particles from the Sun which forms a radiation belt around the planet. The field is much larger that Earth’s and it extents all the way to Saturn’s orbit. The magnetic field is so strong that it is the strongest radio source in the solar system.

Jupiter rotates differentially, which means that it rotates faster at the equator than at the poles.

The great Red Spot on Jupiter rotates around the planet at the same rate as the interior of the planet. The Red Spot rotates around Jupiter at about the same rate as the clouds at the planet’s poles, a little slower than the equatorial zones rotate.

Compared to Saturn, Jupiter has a more circular orbit. Saturn’s orbit is more elliptical and its tilt is larger than Jupiter’s. ( Jupiter’s axis of rotation is almost perpendicular to its orbit.) In addition, the semi-major axis of Saturn’s orbit is nearly twice that of Jupiter’s.

Like Jupiter’s rocky core material, Saturn’s core differs from Earths rocky material by being hotter and denser due to extreme pressure. Saturn also has differential rotation. Which means that its equator rotates faster than its poles.

Saturn radiates more energy than it absorbs from the Sun. Like Jupiter, Saturn radiates more energy than it absorbs. This is due to gravitational collapse. But unlike Jupiter, Saturn has helium precipitation. Even though its almost the same size as Jupiter, Saturn is less dense and has only about 1/3 the mass. This means Saturn’s gravity is about 2.5X less than Jupiter’s gravity.

Titan, Saturn’s single large moon, is the second largest moon in the solar system and has an atmosphere because it is very cold. Titan may also have organic molecules in its atmosphere due to the interaction of the sunlight with methane in the upper atmosphere.

Saturn has several medium sized moons which are tidally locked into synchronous orbits. Encedalus has a highly reflective surface, the result of water volcanoes making one hemisphere much younger than the other which is highly cratered. In addition Encedalus appears to be adding material to Saturn’s E ring which is densest near this moon.

Saturn’s rings are composed of icy particles about the size of snowballs which are found in the plane of the planet’s equator. All of Saturn’s ring are within the Roche limit. The Roche limit is the distance within which the planets gravitational force would tear apart a moon thus forming a ring.

The Cassini division in Saturn’s rings is produced by the gravitational interaction with the moon, Mimas, and the particles in the ring. Any particle in the Cassini division will be under the influence of Mimas which causes the particle to move to higher obit thus leaving a gap in the rings of Saturn. This gap is called the Cassini Division.

The F ring of Saturn is irregular and kinked. Saturn’s F ring and the rings of Uranus are similar in that they are very narrow. The F ring is a result of two small shepherd moons on either side of the F ring keeping it inside its narrow orbit.

Saturn’s strong magnetic field is unique in that its axis is the same as the planet’s axis of rotation. Saturn has a strong magnetic field due to its liquid metallic hydrogen core and fast rotation rate; but the field is much smaller than Jupiter’s. Still Saturn’s field is about 1000 times that of Earth’s field.

The word oblate refers the flattening of a planet or other spherical body; usually caused by rotation. Even though Jupiter has a faster rotation rate than Saturn its oblateness is less. This is because Saturn is less dense than Jupiter.