Supermoon, shmoopermoon? ->
http://blogs.discovermagazine.com/ba...the-supermoon/
Neil, I'm afraid the two moons story has been floating around for a while now
-
http://www.snopes.com/science/astronomy/brightmars.asp or
http://www.hoax-slayer.com/mars-earth-close.html.
Here's an easy way to estimate out the relative sizes in the sky for a pair of astronomical objects (so, not birds or bees
):
D = actual diameter of object, L = distance of object from Earth
approximate angular size (as we see it) ~ D/L [think of the angle subtended by a very small arc of a very large circle].
size ratio of object 1 to 2 (as seen in our sky) = D1*L2/(D2*L1)
So, using the numbers (closest approach distance of Mars for example) in the usual form of this email, we see that Mars will look about 1.4% of the size of the moon. Impressive from an astronomical standpoint, but hardly twin moons eh?