Venus does not have an ocean on its surface!

Today, Venus An arid planet. The desert, however, scientists wonder if in its past, it could not close an ocean. Look a little more like the earth. “No”, To an end Study Conducted by researchers at CNRS and Versailles University of Saint-Quentin.

Before we tell you how these French scientists got there, it is good to remember that another study published a few years ago by American researchers was imaginary. Venus covered by the seas. Climate simulations initiated from there, a Atmosphere Showed that these oceans evaporate and form, as we know them on our planet Clouds Preservatives, which reflect sunlight. “So-called sub-galaxies, especially where the sun heats up very strongly, Explains laboratory researcher Jeremy LegandAstronomy From Bordeaux. A bit like what is happening on earthequatorIn short “.

The work of French researchers does not really contradict each other. “Our colleagues explain that if there were seas on Venus, they would have been able to maintain it, Jeremy Leconde insists. We wondered if the seas had even formed On Venus. And our answer is no “.

What are the chances of an ocean forming on Venus?

“When they form, the planets actually cover themselves with an ocean Magma. A magma decomposes a lot and maintains a particularly dense atmosphere Carbon dioxide (CO₂) And Steam (H.₂0) L ‘Greenhouse effect Serious, Describes usAstronomical physicist. As the planet cools to the point where steam condenses and rains, oceans can form. This is what was played on our earth.

The Climate model The reliance of French researchers on Venus reveals that things did not turn out as expected by the circumstances imagined in the American study. “The only place on the planet where there is not much heat is the night side. Also, in the atmosphere, the side is very high. Stratosphere. From Mass d I was able to get there from the steam loaded day side. Then they formed clouds, but it localized at night. So that they could not produce a protective effect. They were unable to participate in the renewal of Venus. Worse, they created a kind of heat shield that prevented the planet from cooling. Couldn’t rain. No sea can form. “

“If we imagine that there are oceans on Venus like Coin Toss, the US study only said that if the coin falls on the edge, it has a good chance of staying there. Very good. But we say … the chance of the coin breaking is very low., Continues Jeremy Leconde.

Extract information about other planets

Astronomers now want to understand what might be an implication of this study Extraterrestrials. They want to better adjust the limits that water can have Fluid. “Knowing that an ocean did not form on Venus gives us an invaluable clue, Mentions Jeremy Leconde. If our earth was born an a Star Since our sun is there today, it cannot be cold enough to form oceans. Therefore, it is not necessary to have an exoplanet ocean located at the same distance from our star. Even if his star had changed a little – As is the case Red dwarfs, Host stars of the most famous exoplanets – So the planet could not cool itself enough. “

Answering the possible question of the oceans of the past on Venus can also provide important information about the future of our planet. “Studies have already shown us that the earth could end in a billion years – A period that needs to be defined more precisely –, Lose his oceans, Explains the astronomer. In the past, Venus received slightly less energy from the sun. Due to the nature of our star, it is growing Brightness More time. What our planet gets today. In the future, the earth will receive more energy from the sun, just as Venus does today. Thus, by studying the past of Venus, we can clarify when our planet is in danger of losing oceans. “

To confirm their results, French researchers will soon be waiting for data to be collected on site by trips sent to Venus. We know that there is steam in the atmosphere of this planet. But surprisingly few. It is difficult to imagine seas at a depth of a few centimeters. We believe that at some point in history there was more water in Venus’ atmosphere. But she escaped into space and left enoughOxygen To design this oxidized atmosphere we know him, Explains Jeremy Legand.

“One can imagine that new missions to Venus could even measure the chemical composition of its atmosphere and the isotopic composition of some of its components. And when it evaporates, when the sun is very hot, we can imagine water To escape Of its atmosphere. If this had happened before, it would have been further evidence that Venus was unable to seal an ocean. We must now collect these kinds of clues. “

Veritas mission (NASA) and Mission Envision (European Space Agency), According to them, will succeed Infrared, Mineral measurements of the surface of Venus. However, some Minerals Water is needed to form. Detecting their presence is a strong indication of the persistence of liquid water on the planet’s surface. In this case, we do not have to explain the stability of the oceans Remember, this was done by a US study –But at the beginning of Venus’ s history, steam condensed and formed. “, By us Emmanuel Mack, researcher at the University of Saint-Quentin in Versailles, author of the study, by conclusion.