Earth is a unique planet; not only does it support life, but it hosts vast liquid water oceans that cover two-thirds of its surface. These conditions are so elusive that we have yet to confirm a similar environment anywhere else in the solar system today.
The inhabitability of other planets in the solar system besides Earth could have been considerably different in primordial times, and our blisteringly-hot ‘sister’ planet, Venus, is no exception.
Image Credit: GooKingSword/Pixabay
In a new study appearing in the Journal of Geophysical Research: Planets, planetary scientists found that Venus could have had favorable conditions for harboring a surface ocean at some point in its distant past.
They used computer models as the basis of their study. Using their knowledge about planet formation, they simulated a primordial Venusian environment and tinkered with its parameters to find out if oceans were possible. Surprisingly, it could have been.
If Venus had just the right amount of cloud cover, along with the right amounts of carbon dioxide and water vapor in the atmosphere, then these qualities could have kept primordial Venus cool enough to harbor a liquid ocean.
Also read: Could you hear somebody talk on Venus?
Oceans don’t exist on Venus today because the surface is entirely too hot. The long 116-day rotation rate means solar radiation strikes regions of the planet’s surface for extended periods of time. Moreover, the high volume of carbon dioxide in the atmosphere creates a greenhouse effect, trapping heat and warming the entire planet.
Temperatures on Venus push 864º Fahrenheit, but the computer model simulations revealed that a previously-cloudy Venus with just the right atmospheric mix could have sustained much cooler temperatures of around 59º Fahrenheit after planet formation.
At these temperatures, liquid water oceans wouldn’t be out of the question, which has implications for Venus' habitability before things started heating up.
The study doesn’t prove that Venus ever did have surface oceans nor that the planet was once habitable, but it does reveal that such ideas are possible.
Unfortunately, Venus’ environment is so hostile that landers and probes are destroyed by the elements there rather quickly, so exploring the planet is a tricky task. Collecting hard evidence and doing anything besides theorizing will rather difficult to do until we can overcome this obstacle.
Perhaps future advancements in space exploration technology could change that, but for now, it’s nothing but a guessing game.