This is a great video of atmospheric refraction in action

[Stonius (Markus)]

Watch how the moon 'squishes' as it sets behind the earth as seen from space.

http://www.iflscience.com/space/incr...-by-cosmonaut/

[multiweb (Marc)]

Really cool vid. That's the soup we've got to go through to get a decent FWHM. I understand now...

[RB (Andrew)]

Proves the moon is flat too.

[Atmos (Colin)]

Originally Posted by RB

Proves the moon is flat too.

I agree! It shows perfectly well that what is really happening is that there is a change in perspective and you can see that the moon is clearly flattening out!