Venus May Have Been Suitable for Life 715 Million Years Ago
A new study by a team of researchers from NASA revealed that the hottest planet in our solar system, Venus, may have once been suitable for life until 715 million years ago.
The study, submitted in the journal Geophysical Research Letter, suggests that Venus is not as harsh as is it now hundreds of million years ago.
For the study, the researchers created a suite of 3D climate simulations based on topographic data from the Magellan mission, solar spectral irradiance estimates for 2.9 and 0.715 billion years ago and present day Venus orbital parameters. Additionally, the researchers used an ocean volume consistent with current theory and measurements and an estimated atmospheric composition of early Venus.
When the researchers a shallow ocean in their simulation, about 525 meter deep, they discovered that the planet could have remained habitable at its current rotation period of 243 Earth days until the waters boiled about 715 million years ago.
"There's no reason that life on this world would not have existed in these oceans. But that's about all you can say," said Michael Way at the NASA Goddard Institute for Space Studies in New York City, in a report from New Scientist.
Furthermore, with Earth-like landscape and rotation period slower than about 16 Earth days, Venus could have moderate temperatures capable of sustaining life, even with incidents of solar flux 46 to 70 percent higher than what the modern Earth receives.
However, researchers noted that their study is just a couple of "what ifs" and do not prove that Venus is indeed habitable before, but they do show that it could have been.
With their findings, researchers now know that rotation period and topography play a vital role in considering exoplanets in habitable zones. Their study could also shed some light on how life got on Earth and if Venus and Earth is similar in their earlier years, why did they developed very differently from one another.