The atmosphere may be to blame.

Venus’ stormy atmosphere acts like a brake on its rotation.


Venus’ dense and stormy atmosphere is the cause why a day on the scorching planet is longer than a year, a new study suggests.

Venus is a strange and inhospitable world. About as large as Earth, Venus orbits the sun at about two thirds of the distance between our planet and the star. Shrouded in a dense and toxic atmosphere of carbon dioxide and sulfuric acid, the planet suffers from a runaway greenhouse effect that pushes temperatures on its surface to life-preventing 900 degrees Fahrenheit (475 degrees Celsius). And something else is odd about this world: While Venus completes its orbit around the sun in 225 Earth days, it takes 243 Earth days for the planet to spin around its axis. That means that a year on Venus is shorter than a day!

A new study by University of California astrophysicist Stephen Kane now suggests that the thick and stormy Venus atmosphere might be the cause.

“We think of the atmosphere as a thin, almost separate layer on top of a planet that has minimal interaction with the solid planet,” Kane said in a statement. “Venus’ powerful atmosphere teaches us that it’s a much more integrated part of the planet that affects absolutely everything, even how fast the planet rotates.”