While the work on the “Paleo-Venus” were all part of the idea that the water molecules present from the beginning in the atmosphere of the planet had formed by the oceans, a new model comes to contradict them .
by
On the paper, we could take the earth and Venus for binoculars: almost identical size, orbits around the sun quite nearby … Still, rarely we saw Sisters more dissimilar, Eden and Gehenna. Our planet is paradise with its mild temperatures, its well-supplied oxygen atmosphere, its abundant water and a range of living beings, while Venus, closer to the sun, evokes hell: heat such as lead It would be liquid, an overwhelming atmospheric pressure, a drunk air of carbon dioxide and no trace of life or water on its surface. Yet the planetologists have long imagined that, once, the story has started well. That, as on earth, the water had abundantly poured on the white star nicknamed the “star of the shepherd”, before a monstrous greenhouse effect will evaporate the Venusian oceans. A study published Thursday, October 14 in nature comes to contradict this scenario by concluding that Venus probably never saw the sea.
The French and Swiss authors of this article emphasize that the previous work on the “Paleo-Venus” were all part of the idea that the water molecules present from the beginning in the atmosphere had condensed and had formed oceans. Without asking the question of whether this hypothetical deluge could have occurred one day. The fault of models not ripe enough to determine it. In addition, these models were in a dimension: we were only studying air columns. The study published in Nature has benefited from a three-dimensional model, developed for several decades in France at the dynamic meteorology laboratory to simulate the terrestrial climate.
“The physical equations are sufficiently universal so that we can, to some adaptations, use this model for all the planets, specifies Martin Turbet, young French researcher postdoctorate at the University of Geneva and the first author of the ‘The more, compared to models with a dimension, it is because we can see the dynamic traffic in the atmosphere and the formation of the clouds. “There reside the key to the problem.
leak in space
The atmosphere of the young Venus was molecous, molecule that absorbs very well solar energy. “The sun was very strongly heating the high atmosphere of the world’s side planet and prevented the water from condensed,” says Martin Turbet. The clouds therefore formed preferentially night side, in the stratosphere. These high naked behaved like a lid and, by greenhouse effect, forbade the cooling of the atmosphere, which would have opened the valves to diluvian rains. Over time, the molecules of H 2 o of the atmosphere have ended up breaking and their hydrogen atoms by leaking in space. Final result, Venus is dry and has never been “habitable” in the sense that the astronomers hear: too close to our star and too heated by it, the planet has not known the water in liquid form at its area. Water whose “It is considered to be the most important ingredient for the emergence of the living as we understand it on earth,” says Martin Turbet.
You still have 37.45% of this article to read. The rest is reserved for subscribers.