GEOS 112L - Introduction to Earth Science

The flattening of planets:

In class I stated the hypothesis that the shape of a planet can be used to deduce its physical state, whetehr it is mostly solid, liquid or gaseous. In this exercise you will calculate the flattening for all planets and the sun. If you'd like you can also throw in some of the major moons as well.

Planetary flattening (F) can be expressed by the following formula:

where r_eq is the equatorial radius of the planet and r_p is the polar radius of the planet (see figure above). For a perfect sphere both radii are identical and we get a flattening of 0%, for flattened planets r_p is smaller than r_eq and you should get a positive number. Muliplying the result by 100 expresses your result in percent.

Assignment:

1. Which planets would you expect to display smaller degrees of flattening. Make sure to tell me your reasoning.
2. Calculate the amount of flattening for all planets and the sun.
3. Do your results agree with your initial hypothesis?
4. What can you say about the internal structure of the earth, the sun?

What to turn in:

1. A brief formulation of your hypothesis
2. Your calulations (can use Excel and attach a spreadsheet)
3. Your conclusions and answers to questions 3 and 4.