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View Full Version : Was Venus Once a Waterworld?



Fraser
2010-Jun-24, 10:50 PM
Ever read Isaac Asimov's 1950's novel "Lucky Starr and the Oceans of Venus"? Maybe Asimov wasn't so wrong about Venus after all. Analyzing data from ESA’s Venus Express, planetary scientists are looking at the possibility that the planet may have once harbored oceans, and potentially could have been habitable when it was young. (...)Read the [...]

More... (http://www.universetoday.com/2010/06/24/was-venus-once-a-waterworld/)

BigDon
2010-Jun-30, 04:04 AM
If there were oceans of water on Venus, blown off by solar wind, wouldn't it go somewhere?

Did we capture it?

Did it leave the solar system?

It can't fall back into the Sun, as far as I understand such things.

So where did it go?

Enquirering minds want to know.

HenrikOlsen
2010-Jun-30, 12:26 PM
I suspect it got grabbed by anything that could hold on to it, so we got some, the other planets got some, Jupiter getting the lion's share as always, and some blew out into the Oort cloud.

BigDon
2010-Jun-30, 02:45 PM
I'm trying to wrap my head around the dynamics of this, once the water leaves Venus. Part of my brain is trying to tell me to think, 'thick solar wind" but it wouldn't have nearly the same energy as solar wind straight from the source. I guess I'll have to look and see where Mars' atmosphere goes after escaping. (Since that is an ongoing study.)

IsaacKuo
2010-Jun-30, 03:02 PM
I'm trying to wrap my head around the dynamics of this, once the water leaves Venus. Part of my brain is trying to tell me to think, 'thick solar wind" but it wouldn't have nearly the same energy as solar wind straight from the source.
It will after the solar wind gets done pushing on it (it will keep on pushing until they match speeds). Think comet tail.

The escaping gas will zoom outward, escaping the solar system as it eventually gets washed away with the interstellar medium. A fraction will get swallowed up by Jupiter before it escapes; negligible amounts will be swallowed up elsewhere.

Van Rijn
2010-Jul-01, 07:28 AM
There's also radiation pressure from the sunlight. Venus lost hydrogen as it was split off of water (it didn't lose that much oxygen - it's much less likely to escape the Venusian gravity well). Most of the hydrogen would head out of the solar system just because the other planets are so small compared to the volume of space they're in.