Saturn - Chapter 14 Semi-major axis: 9.54 A.U. Orbital Period: 29.5 Earth yrs.

Saturn is much fainter than Jupiter or Mars; its brightness is behind Jupiter, the inner planets, and several of the brightest stars.

Saturn is less than 1/3 the mass of Jupiter. 5.6 x g (95x Earth’s) Radius 60,000km (9.4 Earth radii)

Average density is 0.7 g/cm 3 (less dense than water)

Saturn rotates rapidly and differentially. Rotation of the magnetosphere and the high latitudes is 10 hrs 40 min. At the equator the planet rotates in 10 hr 14 min.

This rapid rotation makes Saturn even more oblate (flattened) than Jupiter.

Saturn probably has a rocky core like Jupiter.

Saturn’s axis is tilted 27° (similar to Earth and Mars) so one would expect seasonal type changes.

Rings - have a thickness less than a few hundred meters, but 200,000 km in diameter.

Atmosphere - much less colorful than Jupiter. No spots, ovals, or contrasting bands. (None visible from Earth.)

Atmosphere is gaseous H 2, He, CH 4, NH 3. H % He - 7% CH 4 & NH 3 - less than 0.25% total (10x as much CH 4 as NH 3 )

There is less percentage of He on Saturn than on Jupiter (14% on Jupiter) or in the Sun. It is believed that the helium sank toward the planet’s center because it is denser than Hydrogen.

The atmosphere is similar to Jupiter’s except it is cooler because the planet is farther from the Sun and the clouds are thicker.

There is a layer of haze followed by layers of NH 3, then NH 4 SH, and then H 2 O ice. These last three layers are 200 km thick total (only 80 km total on Jupiter).

These layers are thicker because of Saturn’s weaker gravity.

Saturn’s clouds are thicker, so there are fewer holes and gaps in the top layer to show through to the more colorful layers below.

This is why Saturn has more uniform appearance than Jupiter. The entire planet has a uniform butterscotch hue.

Weather - The causes are essentially the same as those on Jupiter (rapid rotation and convection). The zonal flow is much faster than on Jupiter.

The equatorial eastward jet stream is 400kph on Jupiter, 1500kph on Saturn.

The first westward flows occur at 40°N and 40°S latitude. 40°N shows the strongest bands and the most obvious ovals, this is the most turbulent area of the planet.

It is not understood why the areas of greatest turbulence are different than on Jupiter.

A large white spot was seen in It was the first one seen since These could be composed of NH 3 ice crystals.

Top Ten Nasa Excuses for Losing the Mars Space Probe.

10. Forgot to attach The Club

9. With all the budget cuts, it was either successful space probe or good office Christmas party

8. Thingamajig on the doohickey musta been on the fritz

7. It got probe-jacked by space punks

6. Should’ve fed in about another ten bucks in quarters

5. According to the official rules, our dads couldn’t help us put it together

4. Must’ve strayed into Klingon territory

3. Mars is smaller than Earth, harder to hit

2. Those lying weasels at Radio Shack

1. Mars probe? What Mars probe?