Astr 1050     Mon., Apr. 26, 2004

Chapter 17: Terrestrial Planets

“Comparative Planetology”

Four Stages of Planetary Development

Timeline

Earth’s Interior

The Active Earth

Earth’s Atmosphere: Greenhouse Effect

The Moon and Mercury

Patterns in Geologic Activity

What is a crater?

Formation of an impact crater

Examples of craters on the moon

Superposition
(way to get relative ages)

Problems with the Condensation Model:
Why is the moon so different than the earth?

Effects of late impacts

Moon: Giant Impact Hypothesis

Relative size of core in Mercury

Venus

Expect Venus to be similar to Earth
(but it isn’t!)

Why does Venus have much more CO2 in atmosphere than Earth?

Surface Relief of Venus from Radar

Volcanoes

Lava Channels

Pancake Domes

“Ticks”

Corona and a possible model

Slide 28

Lots of Martian Science Fiction

Mars and the Pattern of Geologic Activity
and Atmospheric Loss

Why some atmospheres are lost

Which planets can retain which gasses?

Mars atmosphere today

Mars dust storm

Sand Dunes on Mars

Water ice clouds

Ancient River Channels?
(note channels older than some craters – by superposition)

Recent liquid water?
(water seeping out of underground “aquifer” ?)

Layered Deposits

Where is the water today?

“Comparative Planetology”