The slowest rotating planet is Venus, which takes 243 days to complete a full rotation. It is also the only planet in our solar system that rotates backwards relative to the direction of its orbital motion around the Sun.
The other planets have shorter periods because they rotate faster and have shorter orbits. The Earth takes one day for one rotation on its axis, or 24 hours (24 x 60 = 1440). Mercury rotates once every 58 days, while Mars takes about 24 hours and 40 minutes for each rotation. The gas giants Jupiter and Saturn take about 10 hours for each rotation, while Uranus takes 17 hours and 30 minutes to complete a single rotation on its axis.
Earth’s moon takes 27 days, or 12 times as long as it takes to rotate around Earth. This means that when we see one side of the moon from Earth it is actually facing away from us and vice versa — we never see both sides at once!
Last modified: October 28, 2022