20 March 2011


Posted by Ryan Anderson

Hey folks, did you know that tonight, the Earth doesn’t have just any moon? No, tonight we have a SUPERMOON.

What’s that you say? The moon looks just like any other full moon? Well, clearly you haven’t been paying attention. You see, the “supermoon” phenomenon means that it will be ever-so-slightly larger in the sky than normal. This is because the moon will be at perigee: the closest point to earth in its slightly elliptical orbit. Not only does this make the full moon slightly larger than normal, people have been claiming that the vastly increased gravitational pull of the the moon as it swings low over the earth will trigger earthquakes and tsunamis, the likes of which haven’t been seen in oh, say, a week or so.

Um yeah. No. Head over to my friend Ryan Yamada’s blog for his two-part post on the Physics of the Supermoon for the details.

Also, for those of you oohing and ahhing over the supermoon tonight, a public service announcement: observing the full moon is actually not nearly as cool as looking at the moon when it is only partially lit. This is because a) the full moon can be painfully bright in a telescope, and b) the full moon has no shadows to throw the rugged topography of the moon’s cratered highlands into relief. Me, I prefer a crescent moon myself.