It’s Super Moon! It’s tonight!

Tsunamis!  Earthquakes!  Werewolves!  Really bad news reports!

The world may come to an end!

Or not.

The full moon that makes it’s appearance tonight will seem about 14% bigger than when it’s at it’s furthest distance from the Earth.  The tides will be affected by maybe an inch in most places, and up to 6 inches in some geographically odd locales.  Beachfront residents might want to move the chaise lounges back a foot, just to be safe.

It didn’t cause the recent Japanese earthquake.  Any quakes that happen today won’t have been caused by it’s nearness.

There’s something you need to remember about the Moon, tonight’s super fullness, and the effect it has on the Earth.

It’s always there!

The Moon orbits the Earth*  in an ellipse.  The closest point is 220,000 miles, and the furthest point is 254,000 miles.  That’s a difference of only 34,000 miles.  The “closest to the Earth in 20 years” stuff is only related to the orbit reaching perigee (closest approach) at the Full Moon.  It gets that close to us once a month!  It’s merely differently lit by the Sun as seen from Earth this time, and the gravity is tugging  straight on instead of sideways.  There is no special effect transmitted to the Earth by the mere fact the Moon is directly in line with the Sun and Earth at perigee.  Gravity is a tad stronger, hence the one to six inch higher tides, but that’s it.  The light reflected off the surface of the Moon doesn’t effect the tectonic plates we all ride on, and can’t cause an increase in the number or the severity of earthquakes.

There’s no such thing as werewolves (the really cool show “Being Human” notwithstanding), and statistical studies have shown no real “full moon effect” on emergency room visits or police calls.

Basically, it’s all in our head.  We think it’s going to be crazy on the Full Moon, so we remember the crazy that does happen, and forget when it doesn’t.  Now we have this month’s close approach (remember, it gets this close once EVERY month!) at the Full Moon to generate news copy, so we’ll remember anything odd that happens tonight or tomorrow, and some will blame it on the Moon.

For a real astronomer’s take on the Supermoon, check out Bad Astronomy.

To see what NASA has to say about the whole thing, check out Super Full Moon.

So relax, check out the Moon at moonrise, just around sunset.  It will be coming up in the East, big, bright, and 14% bigger tonight than most nights.  I’ll probably miss it, because of cloud cover here in central California.  Don’t worry about earthquakes, werewolves, or people going crazy.  They aren’t due to the Moon.  Earthquakes and crazy people are out there all the time, just like the Moon, and there is no relationship between them.  We won’t worry about the werewolves.

At least I won’t.

* Actually, the Moon doesn’t orbit the Earth.  The Moon is not a moon, it’s a planet in it’s own right.  The Earth-Moon system is more accurately a double planet.  Both bodies orbit a common center of gravity, which works out to be not too far below the surface of the Earth.  That makes it seem like the Moon orbits the Earth, and for most purposes that’s the way we talk and think about it, but it’s not technically correct.

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