Thursday, October 22, 2009

Blue Moon this New Year's Eve - December 31st 2009

We'll have a "Blue Moon" on New Year's Eve this year, going by the currently most popular definition of the term, meaning a second full moon within a single calendar month.

That definition is, itself, a misinterpretation from the 1940's, popularized in the 1980's, and debunked more recently once the sources were finally tracked down. But the new definition has stuck and won't be going away.

Still, it's interesting. All the more so to me... I was born under a blue moon. Yes, I feel a particular affinity for the Soprano's theme song.

The moon won't actually look "blue" (unless we have another Krakatoa between now and then), but for a red moon, here's one that I took of the full lunar eclipse on February 20, 2008.  The bright object in the bottom left is Saturn.

I shot the image standing in the middle of 3rd street in Covington with a normal lens, exposing for 5 seconds, which is why Saturn has the smeary star-trail.  For even more info you don't need, the blueish tinge around Saturn is a common problem for astrophotography... "fast" lenses curve the light enough on very bright objects that they get a halo of violet where the UV is pulled into the visual spectrum.  I've got a v-fringe filter that mostly eliminates it in my telescopes, but I wanted a wide enough field to include Saturn, so for this shot I just used a normal camera on a tripod.

From Covington Blog 2009
(Note... I know the link for this post reads "2010".  Before we get another yearly refreshing Mars hoax, I should state that was a mistake I corrected immediately, but I guess the link for the post was already forged.  I always think of New Years as the coming year.  I guess I have an after-midnight cognitive bias.  So to be clear, it will be a second full moon in a month on 12/31/2009.  And the moon will not look blue.  I'd advise bars to stock up on oranges and Blue Moon beer for the event.)