2. Chapter 6VENUS Radius6057 km Mass4.689 X10 24 kg Density5250 kg/m 3 Atmosphere 96% CO 2 3% N 0.1% Water vapor Pressure 90 atm Sulfuric Acid clouds Composition Basaltic rock and Altered materials Physical Features Low rolling hills Two raised craters called Terras Distinct Characteristics Ishtar Terra Taller than Mt. Everest Clockwise spin and retrograde motion Sulfuric Acid clouds Strong lightning storms and acid rain 1-220 mph winds Discovery (Who and When) Prehistoric times Distance from the Sun0.72 AU Temperatures80 – 872 degrees Fahrenheit Orbital Period224.7 days Rotation Time243.0 days (longer than a year) Moons (how many and names) None

3. Physical Characteristics Rolling planes 70% of surface 35% on Earth (continents) Lowlands 20% of surface 65 % on Earth (oceans) Highlands 10% Plains found to be made of K rich basalts and granite Meteorite craters erased by volcanic activity Intense volcanic activity as large as 1000 km diameter - Ishtar Terra 12 km high (Mt. Everest 10 km high) -Shield volcanoes formed by highly liquid lava (like Mt. St. Helens) No direct evidence of plate tectonics, but the term blob tectonics has been used to explain observations

4. Stages of development 1. Differentiation -Heavier elements move towards the middle 2. Cratering - Caused lava to flow by breaking surface 3. Lava flows Evolution of Atmosphere Heat evaporated water Could not convert CO2 Run away green house effect Very dense atmosphere - 10 times less dense than water (Earth 1000X less dense) - We could fly with wings strapped on our arms 350 kph winds at the top of the atmosphere 1-2 kph at the surface

11. Topography Map

12. Venera 13 3/1/82

15. Venera 14 3/5/82

16. Adams crater

17. Alcott Crater

18. Cleopatra Crater

19. Anemone Volcano

20. Volcano Cone Cluster

21. Pancake Volcanoes

22. Tick Volcano

23. Arachnid

24. Alpha-Regio Upland

25. Eistla Regio - Rift Valley

26. Sinuous Channel

27. Parallel Lines