Steven Dutch, Natural and Applied Sciences, University of Wisconsin - Green Bay
First-time Visitors: Please visit Site Map and Disclaimer. Use "Back" to return here.

Orbit and Rotation

Atmosphere of Venus

The Surface of Venus

Topography of Venus

Geography of Venus

  • Venus has numerous volcanoes. Some scientists think the sulfuric acid in Venus' atmosphere may be of volcanic origin.
  • Venus seems to have had a planetwide volcanic episode about 600 million years ago that covered much of its surface and covered its earlier craters.

    Venus and Earth

    Venus and Earth Near Resonances

    So Venus' rotation and orbital motion repeat the same configurations with respect to earth every 2920 days. Almost. But they are not perfect. For example, Venus transited the Sun on June 8, 2004 and will do so again on June 4, 2012. But since the resonance isn't exact, the inferior conjunction date drifts and there will be no transit in 2020 because Venus will be too far from its node at inferior conjunction.

    Dan Brown blathers at length about these cycles in The Da Vinci Code, claiming that they are perfect. But they're not. However, they are close enough to make one wonder if there was a resonance in the past or perhaps will be one in the future.

    Venus' Rotation

    The animation above follows Venus and Earth through one synodic period. Note that because of its retrograde rotation, it takes less than 243 days for Venus to rotate with respect to the Sun. Also note that Venus rotates four times with respect to the earth during a synodic period (i.e., the red reference line points toward Earth four times).

    As Seen From Earth


    Return to Planetary Images Index
    Access Course Notes on Planetary Geology
    Access Astronomy Notes Index
    Return to Professor Dutch's Home Page

    Created 20 May 1997, Last Update 14 December 2009

    Not an official UW Green Bay site