Which planets rotate from west to east and which rotate from east to west?

Answer 1

All of the planets orbit the Sun in a counterclockwise direction, as seen from above the Earth's north pole. However, only 6 of the 8 planets rotate counterclockwise (spin west to east). The 2 exceptions are Venus and Uranus.

-- The planet Venus rotates very slowly clockwise. One suspected reason is that long ago Venus was struck by a large protoplanet or asteroid, causing it to lose its original spin.

-- The planet Uranus still has its rotational speed, but its axis is now tipped drastically by about 98 degrees, which changes how sunlight illuminates the planet's exterior. Again, the cause may have been a collision with a very large object, early in the history of the solar system.

There are some other theories advanced as well. The current one is the "impact" theory as mentioned above. A large impact could change the direction of rotation or "flip " a planet over. If a planet is turned "upside down", then the original counterclockwise rotation automatically appears as clockwise rotation, from the usual viewing point. Obviously the spin axis of Uranus is at an unusual angle, but Venus could have an "axial tilt" of about 3 degrees or about 177 degrees, depending on how you look at it.

For Venus, there are also theories involving "tidal forces" and its very dense atmosphere.

There are theories involving gravitational interactions between bodies in the early solar system. There is a theory based on the "inherent stability" of retrograde rotation in the case of Venus. There are probably other ideas too.

Still, the fact remains that Venus and Uranus do appear to rotate in the opposite direction compared with the other planets, for whatever reason.