Retrograde and prograde motion days. Venus probably began with a fast prograde rotation with a period of several hours much like most of the planets in the Solar System. Venus is close enough to the Sun to experience significant gravitational tidal dissipation, and also has a thick enough atmosphere to create thermally driven atmospheric tides that create a retrograde torque. Venus' present slow retrograde rotation is in equilibrium balance between gravitational tides trying to tidally lock Venus to the Sun and atmospheric tides trying to spin Venus in a retrograde direction. In addition to maintaining this present day equilibrium, tides are also sufficient to
The 50 Most Extreme Places in Our Solar System The 50 Most Extreme Places in Our Solar System The 50 Most Extreme Places in Our Solar System is the title of a science book by David Baker, professor of physics at Austin College and Todd Ratcliff, a planetary geophysicist at the Jet Propulsion Laboratory. The book is divided into nine sections with a few chapters in each section. The divisions are roughly phenomenological. The book is currently available in two translations with a third in progress. Reviews have been positive including being awarded Honorable Mention in Cosmology and Astronomy in the 2010 PROSE Awards and named an Outstanding University