The weather on Venus is one of the aspects of the planet under constant study from Earth-based telescopes and space missions to Venus. The surface pressure on Venus is 93 times higher than the surface of the Earth. In fact, you’d have to travel one kilometer below the surface of the ocean to find a similar amount of pressure. And the atmosphere of Venus is almost completely made up of carbon dioxide. The temperature on Venus can be more than 460 °C, and this must affect the weather on Venus too.
Although carbon dioxide is invisible, the clouds on Venus are made up of opaque clouds of sulfuric acid, so we can’t see down to the surface with telescopes. Everything we know about the surface of Venus was gathered by spacecraft equipped with radar imaging instruments, which can peer through the dense clouds and reveal the surface below.
The weather on Venus is extreme. The entire atmosphere of the planet circulates around quickly, with winds blowing as fast as 360 kilometers/hour. Cloud systems can travel around the planet completely in about 4 days. Spacecraft equipped with ultraviolet imaging instruments are able to observe the cloud motion around Venus, and see how it moves at different layers of the atmosphere. The winds blow in a retrograde direction, and are the fastest near the poles. As you approach the equator, the wind speeds die down to almost nothing.
Because of the thick atmosphere, the winds move much slower as you get close to the surface of Venus. At the surface, the winds only blow about 5 km/h. Because it’s so thick, though, the atmosphere is more like water currents than blowing wind at the surface. So it can still blow dust around and move small rocks across the surface of Venus.
The clouds on Venus are made of sulfur dioxide and droplets of sulfuric acid. It’s these clouds that block our view to the surface of Venus. Very little sunlight gets through these clouds, so if you could stand on the surface of Venus, it would look dimly lit by the Sun. These clouds do rain sulfuric acid, but the rain is evaporated by the heat so it never reaches the surface. It just goes back up into the higher atmosphere and turns into clouds again.
Spacecraft have detected lightning in the atmosphere of Venus, just like we have on Earth.
We have written many articles about Venus for Universe Today. Here’s an article about Venus’ wet, volcanic past, and here’s an article about how Venus might have had continents and oceans in the ancient past.
We have recorded a whole episode of Astronomy Cast that’s only about planet Venus. Listen to it here, Episode 50: Venus.
NASA Solar System Exploration: Venus