In Class:
Question to Ponder
Why do we suspect that liquid water once flowed on the
surface of Mars?
- a) Dry riverbeds are seen on the martian surface.
- b) The martian atmosphere used to be much denser.
- c) Mars has polar caps with substantial amounts of water ice.
- d) Most of the martian surface has a low crater density.
Jupiter
- Innermost gas giant planet
- largest planet in the Solar System
- Not much iron, rock -- instead TONS of Hydrogen
- Very little core; nearly all atmosphere
- All we see is the upper cloud deck
Giant Planet Formation
- in the outer Solar system, rocks and ices solidified.
- more stuff was available, so planetesimals grew larger.
- Jupiter's protoplanetary core was probably larger than Earth
(maybe as much as 10 times?).
- Larger core -- stronger gravitational pull, so the proto-Jupiter
could attract and hold an atmosphere of Hydrogen and Helium
- LOTS of H and He out there, so the planet acculumulated a massive
atmosphere.
Atmospheric Structure
- Latitudinal banding caused by convective motions (upwelling of
warmed gas from the interior), coupled with strong Coriolus effects
from the rapid rotation of the planet.
- Spots are eddies mostly lodged between bands moving in opposite
directions.
- Spots, including the Great Red Spot which is twice as big as
Earth, appear to be long-lived phenomena.
Jupiter's Rings
- Thin and wimpy compared to Saturn's
- Made of smaller particles than Saturn's
- Material should spiral in toward the planet on short timescales.
- Therefore, the fact that we see these rings indicates that they
are being "fed," i.e., somehow material is being added.
- Sources of ring material: moon/asteroid collisions?, material
leftover from planet formation?
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