Re: Venus's atmosphere

[Bob LaMontagne <rlamont@POSTOFFICE.PROVIDENCE.EDU>]

Frank Cardulla wrote:

> Why is it that Venus has been able to retain an atmosphere that exerts a
> pressure about 90x that of the atmosphere on Earth?  The mass of Venus is less
> than that of Earth, so its gravitational acceleration is only 8.9 m/s2.  Its
> atmosphere is hotter (about 737K vs. 288K).  Even though its atmosphere is mostly
> CO2, with a molar mass of 44 compared to an average of about 29 for Earth's
> atmosphere, it seems counterintuitive that it could retain such a dense
> atmosphere compared to Earth.  Even when you factor in that at higher temperatures
> gases exert greater pressure with less molecules/volume, this is only a factor of
> about 2.5.

Earth has an ocean and vegetation that can sequester the CO2. Venus is too close to the
sun to do that so the CO2 ends up as a major component of its atmosphere.

Bob at PC