Venus, which is the second closest to the sun in the solar system after Mercury, is currently a harsh planet with high temperature and high pressure. But a new study that simulated Venus and Earth’s environment 4 billion years ago shows that Venus has never had an ocean in history since its inception.
Because Venus’ atmosphere is mainly carbon dioxide, a strong greenhouse effect occurs, the surface temperature reaches close to 460 degrees, the atmospheric pressure near the surface is 90 atmospheres, and the sky is a harsh planet covered with thick sulfuric acid clouds. On the other hand, Venus is also called Earth’s sister planet because it has the closest orbit to Earth and is a terrestrial planet with similar size and average density.
Recently, space agencies around the world are paying attention to Venus, and the possibility of the advent of a Venus probe rush is also pointed out. One of the reasons is that when the sun was younger and darker than it is now, Venus may have been a planet warm enough to have oceans that were not very hot, so it is hoped that the exploration of Venus could give important hints about the conditions for life.
Standard solar models suggest that 3.5 billion years ago, the sun was only 75% brighter than it is today, and past research has suggested that Venus may have had an ocean under these conditions. However, if the sun is 25-30% darker than it is now and generates less heat, the Earth further away from Venus should be an ice ball, but there is evidence that liquid water existed on Earth at this time.
Thus, a research team at the University of Geneva in Switzerland simulated the climate of early Earth and Venus 4 billion years ago. The team simulated primordial Venus and the Earth’s environment using sophisticated three-dimensional atmospheric models, such as those used by meteorologists to simulate global climate and future changes.
As a result, it was discovered that Venus had water in vapor form due to the high temperature at that time, and that the entire planet was like a giant pressure cooker. Venus needed to cool over thousands of years, causing atmospheric water vapor to condense into clouds and rain on its surface. Cooling only occurs when clouds form that block sunlight, but on Venus, clouds form only on the cooler night side, creating a powerful greenhouse effect on the night side that blocks sunlight, warming the entire planet.
It was concluded that no oceans were formed, rather than vapors raining down on Venus and pouring it onto the surface. Instead of turning the Earth into a ball of ice, the dark sun allowed the planet to cool properly, turning water into liquid and creating oceans. If the Earth had been closer to the sun or the sunlight was stronger, the Earth would not have gotten colder, so it is fortunate for the Earth that the sun was dark.
The research team points out that it has been pointed out that the darkening of the sun billions of years ago was a failure in the creation of life on Earth called the weak young solar paradox. But the weak sun may have been an opportunity for life trying to form on a very hot Earth, he said, claiming that this study overturns existing views.
The research team said that this result is based on a theoretical model and is an important element to answer the history of Venus. . Related information can be found here.