Originally posted by sir_chancealot
I don't know. Earth's atmosphere is pretty thick, yet we can make out all kinds of stuff on earth pretty clearly from space.
Have you ever looked through a telescope? The images even on a good night are far from crystal clear even from the tops of mountains. The earths
thick atmosphere distorts planetary surfaces and deep sky objects etc. Also from space the Earth's atmosphere is visible as a 'halo' around the
Earth.
Now, if the Moon had a substantial atmosphere the craters and mountains would show erosion and changes, dust storms and clouds would blow up. Indeed
the whole surface would change and we would have to draw up revised Moon maps. The fact is we don't, the maps of the Moon made in the 1800s are just
as valid today because the lack of atmosphere means that the Moons surface never changes- don't forget Mars has a very small atmosphere but we can
see the dramatic changes from here on Earth with small telescopes even at this distance! Imagine the changes we would see on the Moon this close!
If the Moon had even a slightly substantial atmosphere it would be obvious, epsecially during an eclipse- as the Moon passed in fron of the sun it
would illuminate the lunar atmosphere creating a halo effect around the Moon. Again, this doesn't happen as there is no substantial atmosphere.
Originally posted by sir_chancealot
Edit to add: This brings up another point I've just thought about. Why, when you view videos shot from space, of the dark side of the earth, don't
lights on earth "twinkle" like the stars do? You would think that the "twinkle" would work both ways, if it was due to atmospheric distortion.
[edit on 26-9-2008 by sir_chancealot]
That's the quality of the video- they do twinkle slightly but not as much. Don't forget stars are much more powerful! Moreover they are a long way
away. Not all stars twinkle the same amount either- stars high up in the sky hardly twinkle at all while the ones low and the horizon really sparkle-
this id due to the fact that starts lower on the horizon are passing through more of the Earth's atmosphere and their light gets refracted more than
than the stars overhead. So, lights from cities are like the stars overhead only a small amount of refraction. If you were to see them on the earths
'horizon' in space I think they would twinkle much more.
Hope this helps! I should steer clear of the Moon has a thick atmosphere nonsense if I were you- it's just not borne out in reality!
Timelike
[edit on 27-9-2008 by timelike]