Venus is similar to Earth except for atmosphere, oceans, temperature, etc. (mass, surface gravity, etc.), but the surface temperature on the planet's surface is 450°C and the atmospheric pressure is 90 times that of Earth. It is truly a hellish landscape, but how did this happen?
First, the sun gradually gets hotter and larger. Then, first of all, Venus is affected. First, to understand this, we need to understand the greenhouse effect. The greenhouse effect is that the sun (its own host star) heats up the surface of the planet. As it does so, the surface emits infrared radiation. This is absorbed as heat by the greenhouse gases in the atmosphere, such as carbon dioxide, methane, and water vapor. Then, infrared radiation is emitted back into space or to the surface of the planet. And it gets hotter.
In addition, as mentioned above, the oceans are responsible for fixing the greenhouse gas carbon dioxide to the surface, but as it disappears, carbon dioxide from volcanic activity will continue to accumulate in the atmosphere. Also, because atmospheric water vapor is light, it accumulates in the upper atmosphere, but due to photolysis by the sun's rays, the light hydrogen escapes into space. But we do not know where the oxygen went from within the atmosphere. And water generates (possibly activates?) the planet's magnetic field. I can't explain Mercury's magnetic field) role. But Venus is thought to have lost water from its surface at an accelerated rate because it could no longer hold a magnetic field.
Another possibility for life is that life on Earth began 4 billion years ago. The loss of Venus' oceans and water is believed to have occurred between 3 billion and 2 billion years ago. So, life is a possibility. As for evolution, it is possible that it may have evolved as microorganisms. However, the Cambrian explosion on Earth occurred 700 million years ago, so there is no possibility that it evolved into a life form with eyes. However, we do not know if the Cambrian explosion can be superimposed on other planets. The most amazing exploration in the past was probably Venera 13. Before that, Venus was said to be a habitable rocky planet or to have water, but the American Radio? telescope had suggested that Venus might be above 100 degrees Celsius. The opinion was that it was.
This is how thermal stability is maintained in the atmosphere. In the hydrosphere, carbon dioxide is absorbed into the oceans by rain and fixed on the surface of the earth. Carbon dioxide is also increased by volcanoes. But because the sun is getting hotter, the amount of water vapor increases because of the increased incidence on the planet (Venus). And since water vapor is a greenhouse gas, it will continue to get hotter. And so Venus's oceans disappear, leaving only water vapor in the atmosphere.
Also at that time, the former Soviet Union and the EU and NATO were in the Cold War, and space exploration was a competition. The Development Bureau of the former Soviet Union and NASA of the United States sent probes to Venus. NASA was the first to reach Venus, but the former Soviet Union was the first to observe the surface. It was the Venera Project of the former Soviet Union. In the beginning, there was no clear information about atmospheric pressure and temperature, and the spacecraft was crushed by the Venusian atmosphere or failed (to be precise, the failure at the time of launch and the design error of the spacecraft). Also, spacecraft that have landed on Venus have been crushed by the extremely high atmospheric pressure. To solve this problem, most of the instruments of the probe were removed and designed to withstand the atmospheric pressure. It was also designed to withstand high temperatures. Venera 13 landed on the surface of the earth, and has been successful in its observations of the surface of the earth. However, due to the high atmospheric pressure and temperature, it was not shaped like a Mars rover. Moreover, the observation time was only a little over an hour. The temperature is 450 degrees Celsius and the atmospheric pressure varies from 89 to 95, depending on the website.
Also, I think super-rotation is a characteristic phenomenon of Venus's atmosphere. The Japanese Venus Observation Satellite AKATSUKI may have elucidated this phenomenon. However, I am not familiar with planetary meteorology, so I do not know the reason why super-rotation occurs. However, what I can say is that the fate of Venus is likely to be visited on Earth. It is said that Earth will also be out of the habitable zone in 1.3 billion years.
Venus
Moderator: Franck