What is the relationship between the moon's surface gravity, lack of an atmosphere, and temperature range?
1 Answer
Lack of atmosphere and temperature range are strongly related and gravity has nothing to do with either.
Explanation:
On Earth the atmosphere deflects heat from the sun and absorbs heat from the planet. This is what moderates temperature ranges. On a planet like Mercury, with it's atmosphere stripped away by the sun, the side facing the sun is 600 degrees warmer than the dark side.
I am so glad you asked about gravity. Conventional wisdom would have us believe that a celestial body requires more gravity to have more atmosphere. There appears to be some logic in this, however it is false.
Titan is a moon that is about 50% larger than our moon. In theory it should barely have any atmosphere. In actuality it has an atmosphere with 50% more mass than the Earth's atmosphere.
The dwarf planet Pluto has much less mass than our moon. The atmosphere of Pluto is only 1/100,000 of Earth's atmosphere but it is still 1,000,000 times greater than the atmosphere of our moon.
Finally, Venus has a mass just slightly less than Earth. It's atmosphere is 92 times greater than the Earth.
These examples clearly demonstrate that gravity has very little to do with atmosphere.
