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I have to admit i know nothing about this, so i want to ask what feels like a dumb question: What stops water from evaporating into space? I feel like the answe
by verelo 9y ago
I have to admit i know nothing about this, so i want to ask what feels like a dumb question: What stops water from evaporating into space? I feel like the answer is something simple like "gravity", or "condensation", but we seem to think Mars once had water, so where is it now, and will that happen here too?
- cstejerean 9y agoGravity and a magnetic field. Gravity keeps the atmosphere from floating away, and the magnetic field protects it from getting stripped by solar radiation. The problem on mars is he magnetic field.
- verelo 9y agoMagnetic field, ah! Right so, interestingly does that mean a polar shift (that every now and again people rave about) might have larger implications than breaking electronics? Ie massive water loss? I feel like it would depend what the poles look like after the shift, is it likely the field could be weakened or would it just flip? I should probably try learn more about this.
- oldcynic 9y agoThere are tiny losses from the upper atmosphere, but not enough to matter. If you look at the water cycle[0], you'll see that as the water vapour rises it condenses - it gets quite cold a few miles up. Clouds consist of tiny droplets of liquid water and ice, not vapour. [0] https://en.wikipedia.org/wiki/Water_cycle https://en.wikipedia.org/wiki/Water_cycle
- verelo 9y agoRight, that makes sense, and i should have considered the extreme cold of the upper atmosphere. Thanks!