1. Venusian
Geography and Geology

2. Principles of Venusian Geography
Recent images from the Magellan radar satellite mapping probe reveal the Surface of Venus
Two Things differentiate the Surfaces of Earth and Venus
Venus is dominated by Volcanic Terrain
Volcanoes, Lava Plains and Domes etc.
Venus has little evidence of Plate Tectonic Activity
No long Mountain Ranges etc,
Craters are few indicating that the volcanism keeps the surface new…at most a ½ billion years old.

3. Special Features of Venus
1. Vast Lava-domes, Like these “pancakes”

4. 2. Lava Plains .“Fractured” by long narrow valleys

5. 3. Large Volcanoes, such as Maxwell Montes below
Rocks analyzed by the Russian “Venera” probes were Volcanic
Confirming that these features are Volcanic in Nature .

6. Venusian Geography
Venus is mostly rolling Plains, with 2 major highlands:
Ishtar: In the North, Greenland sized, contains Maxwell Montes
Aphrodite: Equatorial, and So. American sized.

7. The Venusian Interior
Two Hypotheses explain why the surfaces of Earth and Venus are so different:
The “Hot Spot Eruption Cycle” Hypothesis
The “Wet Rock/Dry Rock” Hypothesis
Both require a crust thicker than Earth’s
Thus We think that the Venusian Interior is like Earth’s but with a thicker crust.
This thick crust hasn’t broken into pieces thus…
No plate tectonics

8. Notice the thickness of the crust relative to Earth’s