Astronomers led by UNIGE and NCCR planets explore the past Venus Find out if our sister planet has oceans on Earth.
Venus can be seen as the evil twin of Earth. At first glance, they have the same mass and size because our home planet, which is mostly made of rock, contains little water and no atmosphere. However, a closer look reveals significant differences between them: the denser atmosphere of carbon dioxide, the maximum surface temperature and pressure and sulfur. Sour Clouds are completely different with the conditions necessary for life on earth. However, this is not always the case.
Previous studies suggest that Venus may have been a more hospitable place in the past with its liquid waters. A team of astronomers led by the University of Geneva (UNIGE) and the National Research Center (NCCR) in Switzerland have studied the planets to see if the twins on our planet actually have a moderate menstrual cycle. The results are published in the journal Nature of nature, Suggested that it was not so.
Venus has recently become an important research topic for astronomers. ESA and NASA This year, it has decided to send three space exploration missions to the second planet closest to the Sun in the next decade. Whether or not Venus created an early sailor is one of the key questions these missions answer. Astronomers led by Martin Dorbet, a researcher in the field of astronomy at the Unisex School of Science and a member of the NCCR planets, sought to answer that question with instruments on Earth.
Martin Dorbet Four billion years ago, when the surface of the planets melted, we simulated the Earth and Venus climate. “The high temperature associated with this is that any water would have been in the form of steam as it is in a pressure cooker.
Just as scientists use complex 3D models of the atmosphere to simulate Earth’s current climate and future evolution, the team studied how the atmospheres of the two planets formed over time and how the oceans formed in the process.
“Thanks to our simulations, we were able to show that climatic conditions do not allow steam to condense in the atmosphere of Venus,” says Martin Dorbet. This means that the water in its atmosphere is not large enough to form raindrops that can fall on its surface. Instead, water was a gas in the atmosphere, and the oceans never formed. “Clouds favorable to the night sky of the planet are a major factor in this. These clouds have a very strong greenhouse effect, preventing Venus from cooling as previously thought.
Minor differences with severe consequences
Surprisingly, the simulations of astronomers also reveal that the Earth could easily have experienced the same fate as Venus. If Earth were a little closer to the sun or if the sun was still brighter in “youth” our home planet would be very different today. It was the relatively weak radiation of the young sun that allowed the earth to cool, suppressing the water produced by our oceans. Emilyn Polmond, a professor at Unigil, a Planes member and co-author of the study, is the opposite of what we have long called the “dim solar paradox of youth” that has always been a major obstacle to life on Earth. ! But it would have turned the earth into a life-threatening glacier.
“Our results are based on theoretical models and are an important building block in answering the question about the history of Venus,” said David Erinrich, professor of astronomy at UNIGE and a member of the NCCR Planets, co-author of the study. “But our computers can’t control this matter for sure. Observations of three future space missions to Venus should confirm or disprove our work.”
Note: “Day and night cloud asymmetry prevents early seas on Venus, not Earth.” Nature of nature.
DOI: 10.1038 / s41586-021-03873- w
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