Venusian Geography and Geology

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.

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

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

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 .

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.

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

Notice the thickness of the crust relative to Earth’s