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Venus ♀

  • 0.72 AU from the Sun
  • Goes through phases like the Moon
  • Orbits the sun in 225 days
  • Rotational period: 243 days
    • Measured by bouncing radar signals off the planet
    • Day is longer than a year!
  • Spins east --> west

Atmosphere

  • 96% carbon dioxide
  • Covered by clouds
    • Reflect ~70% of the sunlight
    • Makes it harder to study from a distance
  • Very dry
    • Absence of water is one important way it differs from Earth
  • Huge troposphere
    • Region of convection
    • Extends up to at least 50 km
  • About 90x the atmospheric pressure of Earth
    • Like being 1 km underwater

Surface

  • Surface is hot --> 730K (over 850˚ F)
    • Thanks to the runaway greenhouse effect
      • Worse than on the Earth
      • Produces more greenhouse gases
      • Since Venus has so much carbon dioxide the effect is almost a million times stronger than on Earth
    • Melting crust
  • 75% of the surface consists of lowland lava plains
  • Has persistent geological activity
    • Surface age is between 300 and 600 million years
  • No plate tectonics
    • Weak mantle convection

Astronomy Space Planet