1. Sponge: Describe the surface conditions of Venus.

2. Surface Features Mostly smooth, rolling plains. Modest highlands and lowlands.

4. There are two elevated, continent- sized regions. They make up only 8% of the total surface area.

5. The Ishtar Terra is found in the northern hemisphere and is about the size of Australia.

12. One significant feature of the Ishtar Terra is the Cleopatra Crater, a volcanic crater that is 100 km across.

14. The other elevated region is the Aphrodite Terra. It is Africa-sized and is located along the equator.

20. Most of the features on Venus are named after famous women.

21. Map projection of Venus showing Ishtar and Aphrodite Terrae

22. Topographical map of Venus showing Ishtar and Aphrodite Terrae

23. Volcanic activity The most common volcanoes are shield volcanoes.

24. Shield volcanoes are formed when lava wells up through a “hot spot”. Many successive lava flows build up high mountains.

25. A caldera (crater) is formed when the lava recedes.

26. The largest structures are coronae. These are upwellings of mantle material and are structures unique to Venus.

28. Some craters are meteorite impact craters. Some of these are oddly-shaped probably because the meteorite broke up in the harsh atmosphere.

32. There are no small impact craters. No small meteorite could make it through the atmosphere to the surface.

33. There is evidence of volcanism today. The levels of SO 2 fluctuate greatly. There are also bursts of radio energy from the highlands. BUT...

34. No erupting volcano has been observed.

36. The Soviet landers found the surface to be dry and dusty.

37. The samples of crust tested were of two types: Basalt - volcanic material formed later in the planet’s history. Granite - the original crust material.

40. There is no magnetic field, probably due to the slow rotation rate. This means there is no magnetosphere, so there is no protection from the solar wind.