EXONEWS FLASHBACK Article by Sarah Knapton September 22, 2019 (telegraph.co.uk)
• New computer modelling by NASA Goddard Institute for Space Science presented at the European Planetary Science Congress suggests that the planet Venus may have been habitable for billions of years. “Our hypothesis is that Venus may have had a stable climate for billions of years,” said lead researcher Dr Michael Way.” “Our models show that there is a real possibility that Venus could have been habitable and radically different from the Venus we see today.”
• Computer models of the climate history of Venus, the second planet from the Sun, show that until around 700 million years ago temperatures ranged from 68F to 122F, cool enough for liquid water. Venus’ oceans may have lasted for two or three billion years. However, Dr Way says that “in all of the modelled scenarios, we have found that Venus could still support surface temperatures amenable for liquid water.”
• 715 million years ago, the atmosphere of Venus would have been dominated by nitrogen with trace amounts of carbon dioxide and methane – similar to the Earth’s today – and these conditions could have remained stable up until present times. But Dr Way believes that intense volcanic activity around 700 million years ago transformed Venus by releasing carbon dioxide from molten rocks into the atmosphere. The magma solidified before reaching the surface, creating a barrier that prevented the gas from being reabsorbed, causing runaway global warming.
• In the 1980s, NASA’s Pioneer Venus mission found hints that the planet once had a shallow ocean. Because the planet receives far more sunlight than Earth, scientists believed it evaporated before life could be established. With no water on the surface, carbon dioxide rose in the atmosphere, triggering a runaway greenhouse effect that created a crushing carbon dioxide atmosphere 90 times as thick as Earth’s, and temperatures at the surface reaching 864 degrees Fahrenheit, making life impossible.
The planet Venus may have been habitable for billions of years, Nasa scientists have calculated.
New computer models of the climate history of the second planet from the Sun, show that until around 700 million years ago temperatures ranged from 68F (20C) to 122F (50C), cool enough for liquid water.
In the 1980s, Nasa’s Pioneer Venus mission found hints that the planet once had a shallow ocean, but because it receives far more sunlight than Earth, scientists believed it had quickly evaporated before life could become established.
With no water left on the surface, carbon dioxide rose in the atmosphere, triggering a runaway greenhouse effect that created current conditions.
Today Venus has a crushing carbon dioxide atmosphere 90 times as thick as Earth’s and temperatures at the surface reach 864 degrees Fahrenheit (462C), making life impossible.
But new computer modelling by Nasa Goddard Institute for Space Science suggests that the ocean may have lasted for two to three billion years.
Not only does it suggest that life could have once evolved on Venus, but it opens up new possibilities about where aliens may exist outside of our Solar System.
“Our hypothesis is that Venus may have had a stable climate for billions of years,” said lead researcher Dr Michael Way.
“It is possible that the near-global resurfacing event is responsible for its transformation from an Earth-like climate to the hellish hot-house we see today.
“Our models show that there is a real possibility that Venus could have been habitable and radically different from the Venus we see today.
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