Thanks to Allen, a retired high school science teacher from Ovid, all of us will now be able to explain why the moon appears to be so large when it's just above the horizon.

This came up the other day when I commented about how cool the full moon was on Monday night, as it was rising to the east. It was huge! I always thought the reason the moon appears so large, when it's close to the horizon, was because you're viewing it through a thicker slice of the atmosphere and it's being magnified (I actually told my lovely wife that same thing as we drove to Sam's Club that night)

I was wrong. Imagine that.

According to Allen's email (and Phil Plait's "Bad Astronomy" blog, from Discover Magazine), the reason it looks so large is purely an optical illusion, called the Ponzo Illusion. It's the same thing that makes the sun look so huge as it sets over the ocean. That - and the five margaritas you had.

I won't try to explain the science. Here's Phil's blog to do that.

Thanks, Allen!