posted on Jun, 22 2014 @ 02:25 PM
a reply to: JasonT
Orbitally, the Moon is roughly 385,000 km away, however the orbit is not circular, but an ellipse, so this is an average figure. Difference between
when it is closest (its perigree), to when it is furthest away (its apogee) is about 55,000 km. This equates to approximately 12% difference in the
size of the moon.
There is some lensing that happens when we see the moon low on our horizon, through the curvature of the atmosphere.
Because it is so far away, the 'stereo vision' we normally use to judge distance, is ineffective.
This means that we use other objects to compare the size of the moon with, a factor which can give vast variations in perceived size.
Consider the moon high in an open sky. It looks small against the expanse of the stars. If we then consider the moon compared with a tree line, or the
horizon, it looks larger because we see how much of the treeline or horizon it would cover. Compared against a very close window that only reveals a
very small portion of the sky, it could look positively huge.
If all three of these factors were combined (at perigee in orbit, low on the horizon and framed by a near-field window, then the moon may well seem