10.2 Venus: Potential Habitability
Of our solar system, Mercury and the asteroid belt are This has been proven by the deuterium atom
not possibly in Sun’s habitable zone which leaves Venus, concentration in the atmosphere. (Which does not fly
Earth, and Mars. away like hydrogen does)
Why is Venus so Hot? The runaway greenhouse effect
The surface of Venus is too hot for water
Why didn’t earth lose its water like that?
According to inverse square law, (1/0.72 ) there is twice
It’s because outgassed water condensed into rain
as much sunlight on Venus than Earth – equivalent of 30 before UV broke it apart.
However, Venus is almost 470 degrees Celsius. Why?!? Why wasn’t Venus able to do that?
It a result of its greenhouse effect But if Earth and
Venus grew up the same way
Why did Venus remain atmosphere rich with
CO2 while Earth did not?
Venus and earth have equal amount
Earth incorporated CO2 into rock Venus is 30% closer to Sun which is critical point.
because it has oceans and carbon
dioxide cycle On earth, it is cool enough for water to rain down to
Venus is all in the atmosphere because it make oceans in which CO2 dissolved and locked into
rocks. As a result, atmosphere left with less CO2.
has no oceans and thus no carbon dioxide cycle