3 ms·
To first order you can just use the ideal gas law to calculate the average velocity (v_rms = sqrt(3Tk_b/m)) of pick-a-molecule and compare it to the escape velo
by Avshalom 8y ago
To first order you can just use the ideal gas law to calculate the average velocity (v_rms = sqrt(3Tk_b/m)) of pick-a-molecule and compare it to the escape velocity (v_e = sqrt(2GM/r)
- chongli 8y agoAnd then you need to consider the magnetic fields of your blueberry planet. Without them, the solar wind will slowly blast away the atmosphere.
- Avshalom 8y agowell I mean, it's very unlikely to have a magnetic core. That said Wikipedia tells me Mars looses ~.1Kg per second to the solar wind. Bump that up to a Kg/s because the Earth is closer and that still leaves 100 Billion Years before the atmosphere is completely stripped from Earth, so not an immediate concern.
- saalweachter 8y agoRelated: My understanding (from the book Oxygen) is that our oxygen-rich atmosphere keeps our hydrogen (and hence, water) safe. Free hydrogen can’t make it to the upper atmosphere without getting snagged by an oxygen molecule, so we lose relatively little atmosphere, mostly helium - everything else is too heavy.