If a planetoid is too small and too hot then water will escape into space... moons like Europa are massive and cold enough that they have lots of water...our moon however, while more massive, is too warm and water escapes from it into space...
J- Where is the 'boiling point' of water into space for a specific size and temperature of a body in space. In other words how much extra heat energy would it take to 'boil' the Earths atmosphere into space? Any math formulas?
The molecules in the earths atsmosphere scatter she shorter wavelengths (blue) more than they scatter red- giving the sky a bluish color...this is also why the sun looks red when it rises and sets... you are viewing it through more atsmosphere so more of the blue has been scattered out and so it appears redder.
J- How high do we need to go in the Earths atmosphere to attein the same density as that of the Mars atmosphere and what colour does the sky look like from that altitude?
On mars there is MUCH less atsmosphere- most of the scattering of sunlight is done by dust particles... these particles will scatter red more than blue- giving a pink sky...(pretty sure about this- but its been a long time )
J- If there is MUCH less atmosphere on Mars why do the dust particles stay in the atmosphere? I have been under the impression that high density fluid 'suspends' particles and low density fluids allow the particles to 'fall'. How much is the atmospheric pressure on Mars? How was the pressure measured? What would the reading be of a mercury barometer if it was taken there?