The Jovian Planets:
Jupiter, Saturn, Uranus, Neptune
These planets are quite different from the terrestial planets, Mercury, Venus,
Earth, and Mars.
They are big:
- Jupiter: 11 RE
- Saturn: 9 RE
- Uranus: 4 RE
- Neptune: 4 RE
Some of them rotate fast:
They are far away:
- Jupiter: 10 hours
- Saturn: 10 hours
- Uranus: 17 hours; axis tilted, approximately in plane of orbit.
- Neptune: 16 hours
- Jupiter: 5 AU
- Saturn: 10 AU
- Uranus: 19 AU
- Neptune: 30 AU
Jupiter is far away:
It is big:
What does this mean about its density?
- radius ~ 11 RE
- mass ~ 320 ME
It rotates fast:
Jupiter is cold at its cloud tops:
Low temperature at start of solar system would allow
- A day on Jupiter is 10 hours.
We should recall something about the
physics of gases.
- ices to form
- water, H2O
- methane, CH4
- ammonia, NH3
- carbon dioxide, CO2
- gasses to be attracted by gravity to a central core planet more easily.
- This fits with the low density.
- Available gasses are H and He.
- And of course "rock" is also available.
ASTR 121 Home
Davison E. Soper, Institute of Theoretical Science,
University of Oregon, Eugene OR 97403 USA