1. Journal 10/27/16 Objective Tonight’s Homework
If you could take a manned trip to Jupiter, what would you want to study there?
Objective Tonight’s Homework
To learn about Saturn, the second-largest planet
Read Section 12.4 (pp 292 – 299) pp 310: 10, 11, 12, 13

2. Notes on Saturn Physical Properties
Like Jupiter, Saturn is a gas giant. It shares a large number of physical properties with Jupiter, making our analysis easier.

3. Notes on Saturn Physical Properties
Like Jupiter, Saturn is a gas giant. It shares a large number of physical properties with Jupiter, making our analysis easier.
Like Jupiter, Saturn is made of hydrogen and helium. Since the planet is less massive, these gasses are compressed less, giving Saturn a lower density. The atmosphere gets its color from ammonia ice.
Saturn has a mass of about 90 Earths with a radius about 9 times bigger.

4. Notes on Saturn
Wind speeds on Saturn are higher than on Jupiter, reaching speeds of nearly 1500 km/hr at the equator.
Saturn does have lightning storms of gigantic size. They can release hundreds of times more energy than on Earth and last for an entire year.
The last weather feature of interest is called the “polar vortex”. This odd storm swirls around the north pole. What makes it odd is that in the last year or two, it has shaped itself into a perfect hexagon. We have yet to explain this.

5. Notes on Saturn
Rings
The most obvious feature of Saturn is its amazing rings. While we’ve since discovered that all the gas giants have rings, Saturn’s are easily the brightest and most brilliant.
The rings have been analyzed to be composed of 99.5% water ice ranging in chunks from about 1 meter to 10 meters across. The rings extend out from Saturn about 70,000 km, but are amazingly only between 10 m and 1 km thick. On average, the thickness of the rings is smaller than the distance from here to the castle!

6. Notes on Saturn
The material in the rings clumps and separates dynamically, making them appear very bright and young as darker dust gets “shaken off” or moved to the inside of clumps.
In addition to this clumping, Saturn’s moons also cause a lot of gaps and divisions in the rings. There are 3 major rings and dozens of minor ones. We’ll see an image of this on the next slide (broken up into 2 strips to be able to zoom in more.)

7. Notes on Saturn

8. Notes on Saturn You need to know a few of these gaps.
- Cassini Division
The largest gap, between the B and A rings.
- Enke Gap
Near the outer edge of the A ring.

9. Notes on Saturn
Titan
Saturn doesn’t have a lot of large moons, but the one big one it has is very interesting.
Titan is bigger than Mercury but has a mass only half as much. But what’s really interesting is its atmosphere.
It’s 1.5 times thicker than Earth’s, and made almost entirely of Nitrogen.

10. Notes on Saturn
So what makes this so interesting? We sent a probe to Titan in 2005 to finally see the surface for the first time.
The probe found rivers and lakes of liquid methane. The whole planet sort of has a “water” cycle with liquid methane! What makes this even more interesting is that the moon has a lot of complex hydrocarbons. These are often thought of as the building blocks for life. This makes Titan one of the prime places secular scientists are looking for life outside of Earth.

11. Notes on Saturn Orbit-Sharing Moons
There are a few other moons we want to investigate. Saturn has a number of rings that lie just inside and outside some of the thinner rings. These moons help keep the rings intact, by “pinching” the material between them.
Even stranger, some of these moons can switch orbits!
We just want to note here that adding rings and numerous moons causes orbits to get all weird.

12. One last thing…
Saturn’s
moon Mimas

13. One last thing… ?=
Saturn’s Death Star
moon Mimas
!!!!!!!!

14. Living in the Rings Let’s do another survival activity.
Imagine it’s the near future and you’ve been placed in charge of building a mining station in Saturn’s rings. Your job is to tell me everything you’d need to have to be able to set up a workable mining station. You can do this in groups of 2.
Things to consider:
- How will you communicate with Earth?
- How will you meet the needs of the people living there?
- What are you mining? How will get it to Earth?
- Are there other things of interest worth noting? 14

15. Exit Question
Why do we not worry about spacecraft getting destroyed when they pass through Saturn’s rings?
a) Because the rings are too thin
b) Because the ring dust wouldn’t do any damage
c) Because the spacecraft can dodge really fast
d) We just go through the gaps. It’s easy to aim
e) The rings CAN do damage to satellites. Lots