Nº 002 · Space · 50 sec

Why is a day on Venus longer than its year?

Venus, wrapped in bright clouds
Image: NASA/JPL-Caltech · Public domain · Original

Slower than a year

  • One turn on its axis243 Earth days
  • One orbit around the Sun225 Earth days

Measured against the stars, Venus needs longer for a single turn than for a full lap around the Sun.

And backwards, too

Venus spins the opposite way to Earth. There the Sun rises in the west and sets in the east. Among the planets only Uranus does the same. Why Venus turns so slowly and backwards is still not known.

From sunrise to sunrise

117daysis one solar day on Venus

Because Venus spins against its direction of travel, the Sun in a sense comes toward it. So from one sunrise to the next takes "only" just under 117 Earth days. A Venus year holds almost two solar days.

Sources

Every statement in this discovery is backed by one of these sources and was checked before publication.

  1. Wikipedia (German): Venus (Planet) (accessed 2026-10-05)
  2. NASA Space Science Data Coordinated Archive: Venus Fact Sheet (accessed 2026-10-05)
  3. NASA Science: Venus: Facts (accessed 2026-10-05)

Image credits

  • “PIA23791-Venus-NewlyProcessedView-20200608 (cropped).jpg”, NASA/JPL-Caltech, Public domain