๐ Venus May Have Been the First Habitable Planet In Our Solar System, Study Suggests
๐ก Newskategorie: IT Security
๐ Quelle: science.slashdot.org
An anonymous reader quotes a report from The Guardian: Venus is often referred to as Earth's evil twin, but conditions on the planet were not always so hellish, according to research that suggests it may have been the first place in the solar system to have become habitable. The study, due to be presented this week at the at the American Astronomical Society Meeting in Pasadena, concludes that at a time when primitive bacteria were emerging on Earth, Venus may have had a balmy climate and vast oceans up to 2,000 meters (6,562 feet) deep. Michael Way, who led the work at the Nasa Goddard Institute for Space Studies in New York City, said: "If you lived three billion years ago at a low latitude and low elevation the surface temperatures would not have been that different from that of a place in the tropics on Earth," he said. Crucially, if the calculations are correct the oceans may have remained until 715m years ago -- a long enough period of climate stability for microbial life to have plausibly sprung up. "The oceans of ancient Venus would have had more constant temperatures, and if life begins in the oceans -- something which we are not certain of on Earth -- then this would be a good starting place," said Way. With an average surface temperature of 462C (864F), Venus is the hottest planet in the solar system today, thanks to its proximity to the sun and its impenetrable carbon dioxide atmosphere, 90 times denser than Earth's. At some point in the planet's history this led to a runaway greenhouse effect. Way and colleagues simulated the Venusian climate at various time points between 2.9 billion and 715 million years ago, employing similar models to those used to predict future climate change on Earth. The scientists fed some basic assumptions into the model, including the presence of water, the intensity of the sunlight and how fast Venus was rotating. In this virtual version, 2.9 billion years ago Venus had an average surface temperature of 11C (52F) and this only increased to an average of 15C (59F) by 715m years ago, as the sun became more powerful. Details of the study are also published in the journal Geophysical Research Letters.
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