Venus is the second-closest planet to Earth, after Mercury. It’s also the brightest planet that we can see with the unaided eye, appearing as a brilliant white star. The name “Venus” comes from a Roman goddess of love and beauty (incidentally, this is the same goddess that gives her name to Friday, or “Frigida Veneris”). For many people, that’s where our knowledge of Venus ends. They are aware that it has an extremely thick atmosphere and very hot surface temperatures. But what else do you know about this planet? Let’s learn more about the second planet in our solar system and its many fascinating facts.
The Atmosphere of Planet Venus
The atmosphere of Venus is composed of 96% carbon dioxide. This means that if you could stand on the surface of Venus, you would be breathing in almost pure CO2, which is not very good for us. Luckily, the surface of Venus is extremely hot, so the CO2 on the planet does not react with anything and stays in its gaseous state. The atmosphere of Venus is also made up of nitrogen, argon, water vapor, and a small amount of other trace gases. One very interesting thing about the atmosphere of Venus is that it rotates completely opposite to how the planet rotates. What this means is that the planet rotates in the direction of the sun, but the atmosphere is rotating in the opposite direction.
The Surface of Venus
The surface of Venus was probably once like the surface of the Earth, with oceans, rivers, and maybe even life. However, the surface of Venus is now extremely inhospitable. The surface is hot enough to melt lead, and the pressure at the surface is roughly the same as being 900 feet underwater. While the surface of Venus is indeed very hot, it is also extremely dry. There is no liquid water on the surface, and the soil on the surface is almost as dry as the surface of Mars. The surface of Venus is covered in rocks, volcanoes, and craters.
Daytime temperatures on Venus
Venus has an average temperature of 464 degrees Celsius or 882 Fahrenheit. This makes Venus the planet with the hottest surface in the solar system. While this temperature is almost high enough to melt lead, it’s the pressure that really makes the surface of Venus inhospitable. Because of the extreme pressure at the surface, the molecules in the air are very tightly compressed. Therefore, the molecules are very difficult to move around and there is very little circulation at the surface. This means that the surface of Venus is almost like being in a sauna. You can’t really cool off and the heat just builds and builds.
Nighttime temperatures on Venus
The daytime temperatures on Venus are so high because of the thick atmosphere, the greenhouse effect, and the extreme amount of sunlight that hits the planet. However, once the sun sets and the sunlight is gone, the temperatures drop quickly. The extreme pressure at the surface doesn’t change at night, so it doesn’t really allow the heat to escape from the surface. But the greenhouse effect of the atmosphere does stay. The atmosphere on Venus is made up of mostly CO2, and CO2 is an infrared absorber. This means that it absorbs infrared radiation, or the heat of the planet, and keeps it close to the surface.
The History of Planet Venus
Scientists aren’t sure exactly when or how the surface of Venus changed from a habitable planet to one that is almost uninhabitable, but they have a few theories. One theory suggests that the surface of Venus may have been hit by an asteroid or comet early in its history, causing the oceans to evaporate and the surface to change dramatically. Another theory suggests that the thick clouds of Venus are made up of sulfuric acid, making them very corrosive. This could have slowly eaten away at the surface of Venus over time, destroying oceans and any life on the surface. A third theory suggests that as the sun evolved, it emitted more dangerous ultraviolet radiation and this damaged the surface of Venus, making it uninhabitable.
How Big is Planet Venus?
Compared to Earth, Venus is a pretty small planet. It’s only about 1/3rd the size of the Earth, making it the second smallest planet in the solar system, after Mercury. Venus is about 80% the size of Earth, which you might not have known is only the third largest planet in the solar system. Venus is also the second densest planet in the solar system, meaning that it’s almost as dense as a planet can be. The only planet denser than Venus is Mercury. This is because Venus is made mostly of CO2, which is one of the densest substances known.
The second planet in our solar system, Venus is known for its thick atmosphere and extremely hot temperatures. The atmosphere is composed of 96% CO2 which makes it very difficult to breathe. The surface of Venus is covered in rocks, volcanoes, and craters, and is too hot to support liquid water. The history of Planet Venus is a bit of a mystery, as scientists aren’t sure how the planet went from being habitable to almost uninhabitable.