On Venus, a Day Lasts Longer Than a Year
Venus takes longer to spin once than to circle the Sun, and the Sun rises in the west.
The story
Venus is the second planet from the Sun and almost the same size as Earth. But it is one of the strangest worlds in the solar system.
It takes Venus 243 Earth days to rotate once on its axis. But it takes only 225 Earth days to travel all the way around the Sun. One spin takes longer than one year.
Venus also spins backwards compared with Earth and most other planets. If you could stand on its surface, you would see the Sun rise in the west and set in the east.
Standing there would be impossible, though: Venus's thick carbon dioxide atmosphere traps so much heat that the surface is hot enough to melt lead.
The evidence chain
- NASA lists Venus's rotation period as 243 Earth days and its orbital period as 225 Earth days.
- NASA confirms that Venus rotates in the opposite direction to most planets (retrograde rotation).
- These values come from decades of radar measurements and spacecraft missions, including NASA's Magellan.
Verdict
CONFIRMEDBacked by strong, verifiable evidence.
Measured and confirmed by NASA. Why Venus spins backwards is still an open question in planetary science.
Sources
Published 2026-10-24. Spotted an error? Email provenmysteries@gmail.com.