Atmosphere of Venus

Not a nice place to visit, and you wouldn't want to live there.
Venus has a very thick atmosphere:

Here is a comparison of the atmospheric composition of Earth and Venus. I list the number of molecules per m2 of surface area of the planet in each planet's atmosphere relative to the total number of molecules per m2 in Earth's atmosphere.

          Earth       Venus
N2       0.79         2
O2       0.20       < 0.001
Ar        0.01         0.005
CO2      0.0003      64
H2O    ~ 0.02        0.003

Total     1.00        66

H2O      3 km        0.5 mm
+ vapor

(A technical note: This is based on a pressure ratio of 92/1,
a surface gravity ratio of 0.91/1.0, and a mass per molecule
ratio of 1.5/1.0 for Venus/Earth.)
Note that the amount of nitrogen in Venus's atmosphere is a little larger than in Earth's atmosphere, but the amount of oxygen is much less and the amount of carbon dioxide is much more. Also, if you count the oceans on Earth, Venus has a lot less water than Earth.

Venus has clouds 50 to 70 km above surface containing H2SO4 (sulfuric acid).

Where did Earth's CO2 go?

Where did Venus's water go?

ASTR 121 Home

Davison E. Soper, Institute of Theoretical Science, University of Oregon, Eugene OR 97403 USA