After all, Venus may not be a very attractive target for alien hunters.
In recent years, more and more researchers VenusThe second rock from the sun, as a potential dwelling for life.For example, modeling studies suggest that ancient Venus may have had a large ocean and climate. Lasted for billions of years..
Of course, Venus is a famous hell today. Its surface is dry and hot enough to melt lead. However, some scientists argue that the life of Venus, if it exists, may still exist there. Floating in the clouds At a height of about 30 miles (50 km), temperatures and pressures are the same as we enjoy here on Earth’s surface.
But new research casts some cold water on such hopes.
Duel model of ancient Venus
Like all newborn planets, young Venus was very hot — too toasted in a sea of liquid water. Almost all of its available water evaporated, creating a planetary-scale sauna condition.
Earlier life-friendly modeling work found that the planet was cooled enough to host liquid surface water, largely due to clouds, and much solar radiation bounced back into space. NS “The dark sun paradox“This was also a factor. In the early days of our solar system, our stars were only 70% brighter than they are today.
of New researchScientists led by postdoctoral fellow Martin Turbet at the Geneva Observatory in Switzerland, published online in Nature on Wednesday (October 13), used a new model to simulate the climate of ancient Venus. .. And they came up with very different results.
Turbet and his team have discovered that the condition of young Venus is likely to limit clouds to the night side of the planet. There, as far as the establishment of life was concerned, they were worse than useless. (Venus is not properly anchored to the Sun, so there is no permanent night side. The term here refers to the hemisphere facing away from the Sun at that time.)
Not only did these clouds not reflect sunlight, they actually warmed Venus. Greenhouse effect, Confine a lot of heat. As a result, Venus did not cool enough to form rivers, lakes, and oceans when it rained.
“If the author is right, Venus has always been a hole in hell,” said James Casting and Chester Herman, astronomers at Pennsylvania State University and NASA’s Ames Research Center, in the accompanying “News and Views” of the same issue of Nature, respectively. I am writing in the article. (Casting and Herman are not members of the research team.)
A more detailed study of the surface of Venus can give some insight into the ancient climate of the planet. For example, Casting and Herman refer to the “highly deformed region” of the planet called Tessera. These regions are thought to be similar in composition to the rocks of the continents on Earth.
“On our planet, such rocks are formed by metamorphisms that occur in the presence of liquid water (minerals change shape without melting),” writes Kasting and Harman. “If Tessera turns out to be basaltic like the normal ocean floor on Earth, no liquid water is needed to produce Tessera, further supporting Tarbet and his colleagues’ hypothesis.”
NASA’s Newly Selected VERITAS (Short for “Venus Emissivity, Radio Science, Interferometric Synthetic Aperture Radar, Topography and Spectroscopy”) The mission, which will be launched in 2028, will study Tessera from orbit if everything goes according to plan. But to fully understand these interesting features, a Venus lander may be needed, Kasting and Harman write.
Impact on the Earth and beyond
New research also discovered it Earth According to a model developed with Turbet, if the Sun was bright a while ago, it would probably have followed the route of Venus. The young sun, 92% instead of 70% of its current brightness, probably entrusted our planet to greenhouse conditions. His team.
As Kasting and Harman pointed out, this result also affects other sun-orbiting worlds and researchers trying to understand them.
“”Exoplanet Its orbit near the inner edge of the traditional habitable zone, where liquid water may be present on the surface of the planet, may not actually be habitable, “the duo wrote.
Mike Wall says “there“(Grand Central Publishing, 2018; illustrated by Karl Tate), a book on exploring alien life. Follow him on Twitter. @michaeldwall.. Follow us on twitter @Spacedotcom Also Facebook..
Life on Venus may not have been possible
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