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View Full Version : What might very early Venus have been like during the Faint Young Sun Era?



Bad Ronald
2011-Oct-15, 05:10 PM
If Earth was Snowball Earth, & Mars, White Mars(?), then might Venus's climate, weather, & rotation have been like Earth today during the time of the Faint Young Sun?

IIRC the Faint Young Sun had 70% the output of the present Sun. So would a "normally" rotating Venus with oceans & continents back then have been like Earth today? Perhaps colder? Maybe like Earth during ice ages, with extensive polar glacial ice sheets?

Then whatever happened to Venus happened at some point, leading to its current slowtation & climate & weather.

korjik
2011-Oct-16, 05:30 AM
I would imagine that if Venus had an Earth-like rotation, it would be alot more Earth-like even today. I dont know if anyone has ever run the numbers with placing Earth in Venus' place and seen when the oceans would dry up.

Chances are that Venus has always had close to the rotation rate it does today tho. That would make the days very different from Earth at a very young age.

antoniseb
2011-Oct-16, 08:40 AM
Looking at the Hydrogen/Deuterium ratio for Venus, I'm guessing it had a much thicker atmosphere with lots more water in it than it has now.

Githyanki
2011-Oct-17, 05:03 AM
I don't think it would have ice-ages, but a faster-rotating Venus would have a stronger magnetic-shield. I think early Venus was probably 100% covered in water with vast oceans. Like Earth, due to the heat of accretion, it would probably be so hot it's close the point of boiling. Venus probably had life like Earth up to about 2.5BYA when the temperature rose to the point in which the oceans boiled away.

Van Rijn
2011-Oct-17, 08:46 AM
Looking at the Hydrogen/Deuterium ratio for Venus, I'm guessing it had a much thicker atmosphere with lots more water in it than it has now.

I'm not sure it would be much thicker though definitely far more water. It's thought that hydrogen was selectively lost, since hydrogen molecules are low mass. The oxygen though wouldn't be nearly so easily lost.

Githyanki
2011-Oct-17, 05:20 PM
I'm not sure it would be much thicker though definitely far more water. It's thought that hydrogen was selectively lost, since hydrogen molecules are low mass. The oxygen though wouldn't be nearly so easily lost.

So if that's true, could it be possible that Venus once had a super-thick oxygen-rich atmosphere and it's surface could have been stained red like Mars and Pre-Cambian Earth?

antoniseb
2011-Oct-18, 08:37 AM
So if that's true, could it be possible that Venus once had a super-thick oxygen-rich atmosphere and it's surface could have been stained red like Mars and Pre-Cambian Earth?

Pretty tough to have an O2 rich atmosphere. O2 is so reactive. You pretty much need some kind of life to create O2.

chornedsnorkack
2011-Oct-18, 09:15 AM
Pretty tough to have an O2 rich atmosphere. O2 is so reactive. You pretty much need some kind of life to create O2.

Could water photolysis and hydrogen escape have produced oxygen in amounts enough to make atmosphere oxygen rich?

antoniseb
2011-Oct-18, 11:12 AM
Could water photolysis and hydrogen escape have produced oxygen in amounts enough to make atmosphere oxygen rich?
This is not my field, but I'm thinking that if you have lots of Carbon, Sulfur, or Iron, Oxygen is going to get bound to something.