I'm less worried about atmospheric percentages than I am about absolute amounts. Venus's atmosphere is so thick that it drowns a lot of percentages. For example, the last time I did the calculation, Venus has approximately the *same* *absolute* amount of nitrogen in its atmosphere as does the Earth. I'm not worried about helium & neon, as I doubt that they are important for life -- either for or against -- unless you consider the neon lights of sleazy bars & hotels to be important for nightlife. So that leaves us with hydrogen. Once again, it would be interesting to know the absolute amounts of hydrogen on Venus -- including whatever hydrogen is bound up in other compounds -- not necessarily water. I'm not suggesting that the Moon isn't important for life -- it probably is, and probably far more important than the magnetic field for life. The Earth's Moon has had an incredible stabilizing effect on the Earth's rotation and its axis, and the process of formation of the Moon -- most likely a large amount coming from the Earth itself after a massive collision -- may have made things much better for life -- perhaps doing something to get rid of the bulk of the Venus-type gasses in the atmosphere. At 04:19 PM 4/4/2016, Warren D Smith wrote:
And how's that werkin' out fer ya, Venus? I would say that, based upon a comparison of Earth & Venus, that atmospheric stripping theory doesn't hold much water.
--Atmospheric stripping presumably would be most severe for hydrogen and helium and neon. Mercury & Mars both have stripped atmospheres. And Venus's atmosphere contains only 12 ppm helium and well below 1 ppm hydrogen. The latter is far below Earth's atmospheric H percentage. Venus also has 7ppm Neon versus Earth's 18. But Venus's He does exceed Earth's. (Could it be Venus gets "refueled" with He from solar wind?)
-- Warren D. Smith http://RangeVoting.org <-- add your endorsement (by clicking "endorse" as 1st step)