Ancient Venus may have had oceans until 2.9 billion years ago

I saw this article the other day, which, based on a simulation, argues for Venus being able to hold liquid water on its surface until 2.9 billion years ago. If accurate, this has a number of interesting consequences: first, that planets orbiting other stars near the inner egde of the stars habitable ("goldilocks" ) zone may remain habitable for much longer than previously thought. The article makes in particular the case that Venus' slow rotation (a Venus day is slightly longer than a Venus day) would actually - paradoxially - be beneficial for retaining the oceans. This is also something to consider for planets orbiting around very dim stars (M-class stars or 'red dwarfs'), which are invariably going to be tidally locked to their stars, meaning one side would permanently have "day", while the other side would permanently have "night".

user link on arxiv.org

That's pretty damn cool!

I have heard before that Venus and Mars were good candidates for being (somewhat) Earth-like a long time ago. Not to get into that panspermia nonsense but it would be interesting if it were easier for planets to, at least for part of their existence, achieve nearly Earth-like properties.

Long term, if humans are going to colonize other planets in the distant future, stuff like that would be good to have a handle on.

Wasn't Venus likely similar to Earth before a runaway greenhouse effect transformed it into what it is today?

I find it fascinating that, as we learn more about other planets, Earth isn't quite as unique as we previously believed. That greatly increases the possibility that life has occurred in many other places.

On Friday, February 12th, 2016 at 11:41 pm, Nitrocosm said:

Yes, the general idea is that prehistoric Venus was very earthlike up to a certain point (around 2.9 billion years ago, according to the article). Which would mean that the planet had some 1.7 billion years of being earthlike from its formation - which would be enough to have some form of (well, single celled) life going.

Fascinating. Any traces of such life have long since been destroyed by the enormous pressure and corrosive atmosphere, I would imagine.

If only we could send a probe robust enough to survive long enough to dig up potential fossils...