Venus Should Be 'Locked' With One Side Facing The Sun. Here's Why It Isn't

When two bodies in space are close together, their gravity slows them down until one of themlocks.

The reason why we only see one side of the Moon from Earth is because of this tidal locking.

Venus is close to the tidal locking threshold. It was so close that it could have been locked to the Sun.

It takes Venus 243 days to complete one rotation of the Sun, and it takes another 225 days to complete one.

It is a small difference, but significant. The thick, tempestuous atmosphere on Venus is 60 times faster than the planet itself, which is one of the reasons Venus is unable to lock fully.

Stephen Kane, an astronomer at the University of California, Riverside, says that we need to pay more attention to planetary atmospheres when studying distant stars.

Kane explains that the atmosphere is a thin, almost separate layer on top of a planet that has minimal interaction with the solid planet.

The powerful atmosphere teaches us that it is a part of the planet that affects everything.

The atmosphere of Venus is thought to be one of the key characteristics that led to Earth and Venus becoming very different worlds.

This is a puzzle that planetary scientists would love to solve, since it shows the difference between a lush, habitable world and a toxic, acidic hellscape.

The winds on Venus are higher than 400 kilometers per hour.

This super rotation causes the atmosphere to drag on the planetary surface, as well as slowing the planet's rotation, and preventing tidal locking.

A single day on Venus lasts around 118 days because of the slow, retrograde rotation. Most of the heat of the Sun is absorbed by the atmosphere and only 3 percent of sunlight reaches the surface.

Venus has the hottest surface of any body in the Solar System, with an average temperature of 482 degrees Celsius.

Kane says that standing on the surface of Venus would be like standing at the bottom of a hot ocean. You couldn't breathe on it.

Venus has a greenhouse effect because the atmosphere traps the solar energy. We don't know what role being tidally locked might play in contributing to the runaway greenhouse effect, but studying Venus might yield some clues.

Most of the exoplanets we find are very close to their host stars; the tools we use to search for them are much better at finding close worlds. Many of these worlds would be locked up.

Habitability can help us identify planets with a runaway greenhouse effect, since they are inhospitable to life.

Astronomers look for roughly Earth-sized objects when looking for exoplanets. Being Earth-sized is not enough.

Venus is larger than the Earth and any Earth organisms trying to live there wouldn't be able to survive. It is not possible to simply use Earth as a model for exoplanets.

Venus is our chance to get these models correct, so we can properly understand the surface environments of planets around other stars.

We are not doing a good job of considering this. Earth-type models are used to interpret the properties of exoplanets. Venus is waving both arms around.

He says that Venus is a tool that we can use to understand the climates of alien worlds.

Nature Astronomy has published the research.