Planet Venus is not the best world to search for extraterrestrial life. It has a toxic atmosphere 90 times thicker than Earth's and its surface temperatures are hot enough to melt lead.
Oceans On Venus
A new study, however, suggests that once, the Earth's twin likely had stable temperatures and even hosted liquid water as earlier suggested by data from NASA's Pioneer 12 mission.
In 1978, the mission reached Venus and found indications suggesting the planet may have once hosted oceans on its surface.
Study researcher Michael Way, from the Goddard Institute of Space Science, and colleagues created five computer simulations that considered the kind of water coverage Venus had in the past that would have led to its conditions today.
Three of the five simulations assumed the current topography of Venus and considered a deep ocean, a shallow layer of water, and trace amounts of water in the soil.
The researchers then simulated the environmental conditions on the planet using a 3D general circulation model, which accounted for the increase in solar radiation as the sun warmed up, and changing atmospheric conditions.
Potentially Habitable For At Least 3 Billion Years
Many researchers believe that Venus is too close to the sun to support liquid water but the findings of the study suggest this may not be the case. Way said that in all of the scenarios they modeled, Venus could still have surface temperatures that would support liquid water on its surface.
Each of the scenarios suggests that the 4.5 billion-year-old planet could support liquid water and temperate temperatures on its surface for at least 3 billion years, suggesting that ancient Venus was a potentially habitable world.
The planet's climate, however, changed when something triggered the release of carbon dioxide from the rocks about 700 to 750 million years ago.
"Our hypothesis is that Venus may have had a stable climate for billions of years. It is possible that the near-global resurfacing event is responsible for its transformation from an Earth-like climate to the hellish hothouse we see today," Way said.
The findings were presented at the European Planetary Science Congress - Division for Planetary Sciences Joint Meeting 2019, which was held in Geneva Switzerland from Sept. 15 to 20.
