# Planetary atmospheres

How dense could Earth's atmosphere potentially be, as opposed to how dense it is now? Assume that Earth's mass and position in the solar system do not change.

Al

you might start by looking at venus

Matterwave
Gold Member
Well, there is quite a lot of CO2 trapped away in the Ocean...and even more of it trapped away in Calcite deposits. Also, there's a lot of methane trapped in pockets around the world...I would say the Earth's Atmosphere could become quite a bit thicker than it is now...I wouldn't be able to give any numbers though.

Nabeshin
How dense could Earth's atmosphere potentially be, as opposed to how dense it is now? Assume that Earth's mass and position in the solar system do not change.

Al

Do you mean just how much atmosphere could we pack onto the Earth or how much could conceivably outgas from rocks and other sources?

I mean how much could Earth hold onto with gravity and insolation at present levels.

There's an equation (or set of equations) for this, but I can't remember what they are.

Al

I mean how much could Earth hold onto with gravity and insolation at present levels.

There's an equation (or set of equations) for this, but I can't remember what they are.

Al

Not that I know of. Stephen Dole ("Habitable Planets for Man") fitted an empirical equation to the atmospheres of earth, Venus and Mars, but it was of dubious value since it used old data for Mars and Venus.

Earth can hang on to a much more substantial atmosphere, since we know Venus can at twice the insolation. There's about enough CO2 in the crust for a 45 bar atmosphere, thus a bit less than Venus. If the oceans boiled then there would be about 300 bar of atmosphere at about 650 K. But that's unlikely at current insolation levels.