Can you imagine a temperature at which lead melts? Venus is the planet where such a high temperature exists. Although Venus is not the nearest planet to the sun but still it is the hottest planet in our solar system, hot enough to destroy any space probes in very little time. The temperature of Venus is around 471 degree Celsius whereas the temperature of Mercury is 466 degree Celsius in the day, in spite of being the nearest planet to the sun.
The temperature of Venus remains same whether it is day or night, equator or poles. Venus is called the sister planet of Earth but still there is a huge difference in the environment of these two planets.
The question arises why is the temperature of Venus is so high?
The answer somewhere lies in its thick blanket, its ‘atmosphere’. The atmosphere is very different from Earth. It is composed of 97% carbon dioxide, 2% Nitrogen and less than 1% of oxygen, water, and methane. There is also a substantial amount of sulphuric acid in the lower atmosphere which forms clouds and causes a rain of sulphuric acid.Thunders and lightning also exist on Venus which is related to sulphuric acid clouds unlike water clouds on Earth. The atmosphere is so thick that its pressure is 90 times the atmospheric pressure on Earth. This atmospheric pressure can press you as hard as water 3000 feet beneath Earth’s Oceans.
Now after knowing about the atmospheric status of Venus, you will be thinking that how can atmosphere heat up Venus to such a high temperature? But you are missing 97% carbon dioxide and sulphuric acid, both are good Greenhouse Gases. So let us look at it more carefully. The Greenhouse Gases will allow the sunlight to enter into the atmosphere of Venus but will not allow them to go out into space. In this process, heat starts accumulating on the Venus and give rise to high temperature.
The atmosphere of Venus has very high reflectivity, that’s why it reflects most of light of the sun and make Venus brightest object in the sky. Due to its high reflectivity, the surface of Venus is not visible to us. NASA’s Magellan mission to Venus during the early 1990s used radar to image 98 % of the surface, and the Galileo spacecraft used infrared mapping to view mid-level cloud structure as it passed by Venus in 1990 on its way to Jupiter. In spite of thick atmosphere, cyclones of high speed up to 360 km/h exist on Venus, the reason of this is still not clear to the scientist.
The surface Venus is also much different than the surface of Earth. Craters which are smaller than 1.5 to 2 Km do not exist on Venus because small meteors burn up in the dense atmosphere before reaching the surface. It is believed that Venus was completely resurfaced by volcanic activity 300 to 500 million years ago. More than 1000 volcanoes larger than 20 Km in diameter are still present on the surface.
We can see that the Venus is not the place where any life form can survive. Still, it is one of the amazing planets of our solar system.