Although Venus is just next to Earth, there are many things about the planet that are still a mystery. This is due to the thick layer of sulfuric acid clouds which cover the surface completely. This has refrained scientists from knowing basic stuff about the planet – including the length of a day on Venus.
How long is a day on Venus?
However, researchers from the University of California, Los Angeles, now have the answer to this, thanks to their 15 years of observations. The team used radar to bounce off signals from Venus’ surface and were able to determine the length of a day, the size of the planet’s core, and also the axis at which the planet is tilted.
“Venus is our sister planet, and yet these fundamental properties have remained unknown,” said Jean-Luc Margot, a UCLA professor of Earth, leader of the research.
The team found out that a day on Venus is equal to 243.0226 days on Earth, around two-third of a year on our planet. This speed is extremely slow and the planet also spins in the opposite direction to Earth and most planets in the Solar System.
Venus’s thick atmosphere responsible
Moreover, its spinning rate changes over time, with variation in the length of a day of up to 20 minutes. This has made it even more difficult for the researchers to figure out the exact length of a day on Venus. The team believes the planet’s thick atmosphere is responsible for this variation. Venus’ atmosphere rotates much faster than the planet itself, which could be the reason behind the rotation through momentum.
As for the axis tilt, Venus is tilted by 2.6392 degrees and its core is around 2,200 miles across, making it a similar size to our planet’s core. These discoveries were made by firing radio waves at Venus and examining when the waves bounced back so the echo could be detected by telescopes on Earth.
“We use Venus as a giant disco ball,” said Margot. “We illuminate it with an extremely powerful flashlight—about 100,000 times brighter than your typical flashlight. And if we track the reflections from the disco ball, we can infer properties about the spin [state].”
