Why a day on Venus lasts longer than its year

Venus spins so slowly that a single rotation outlasts a trip around the Sun, and it turns the opposite way to most planets.

A slow, backwards spin

Venus takes about 243 Earth days to rotate once, but only about 225 Earth days to orbit the Sun. It also rotates in the opposite direction to most planets, so the Sun would appear to rise in the west.

Hotter than Mercury

Although Mercury is closer to the Sun, Venus is hotter. Its thick carbon dioxide atmosphere traps heat, keeping the surface at around 465 degrees Celsius.

A day on Venus is longer than its year.

Why it matters

Venus shows how much an atmosphere can change a planet, which is why scientists study it to understand climate on Earth.