SUUUUUUPER Moon!

First, the disclaimers — if this hadn’t been completely overhyped by the media, the odds that you would notice tonight’s “supermoon” being brighter or bigger is small. Surfers and sailors might know something’s up, since one of the other effects of a “supermoon” is “astronomical high tides“, i.e., moon a bit closer, gravitational pull a bit stronger, water/tides get pulled more.

The short version:

1. The moon is full today (happens every 29 days 12 hours & 44 minutes).
2. The moon’s orbit is not circular but an ellipse, so sometimes it’s a bit closer to Earth (perigee = 221,796 miles tonight) and sometimes a bit further away (apogee = 252,634 miles on July 27th). It’s been doing that for about 4.4 billion years as far as we can tell.
3. Because it’s slightly closer (it’s not a sudden thing, it’s been creeping up on us for days), tonight the full moon looks 14% bigger than it does on average at full moon.
4. Because it looks bigger, it looks about 30% brighter than does on average at full moon.

14% bigger, 30% brighter. Significant, yes. Noticeable to the average person on the street? Maybe, maybe not.

Having said all of that and done the “pooh-pooh” thing…

Getting this much press sure has gotten more than a few folks interested. I took the camera out (through a telescope, the full moon, “super” or not, looks extremely bright, flat, featureless and boring — no shadows) and drew a small crowd. (Okay, so the annual Halloween & eclipse star parties in the front yard have alerted the locals that I’m “that” neighbor.) I could also see and hear neighbors with small kids up and down the block bringing them out to look and trying to take pictures of their own. (They get an “A” for effort, but pro tip — turn off the flash before trying to get a photo.)

Anything that gets folks out looking at the sky and being aware of what’s going on above them is a good thing. So, go get ’em, supermoon!

Oh, you want pictures? Funny you should ask.

The full moon came up behind the trees to our southeast. Note that he full moon is BRIGHT if you’re using a telephoto lens or telescope. Obviously not as bright as the sun, but if you try to photograph it taking up any decent part of the frame, you’ll need to take really fast exposures to get any detail. All of the closeup photos here tonight were taken at 1/4000 second, the fastest my Canon Rebel XTi DSLR will go. (I was using a Tamron 75-300 zoom lens.)

Next pro tip, especially if you’re using a DSLR – focus manually, don’t let the camera autofocus. You’ll be able to play with it like this…

…and then immediately refocus past the foreground objects. (This picture was taken eight seconds after the one above with nothing changed but the focus.)

Zooming back out and taking much longer exposures, you see the trees silhouetted and a few thin clouds near the moon. (This is a 1/13 second exposure, over 300 times longer than the closeups above.)

Of course, in taking longer exposures to bring out the trees and clouds, especially if you zoom in just a bit (thus brightening the moon), you completely overexpose the moon and start to pick up some “ghost” reflections inside the lens.

The first two pictures above were cropped to show just the moon — this is what a full frame looks like using a 300mm zoom lens. At this point the moon had climbed above the trees and it starts looking a touch less “super,” just big and bright and full.

One other thing that’s not really significant or uncommon, but I liked, was shooting a series of photos about 2.5 seconds apart while a wisp of cloud passed in front of the moon. (If it had passed behind the moon, I would be looking for my Pulitzer and Nobel Prize in the morning.)

I lined them up using Photoshop. Note that I didn’t adjust their vertical position at all. Since the camera was locked down on a tripod, you can see the upward motion of the rising moon even over just a 25-second period. Proof that the Earth rotates!

If it’s not too late where you are (or you could do it tomorrow, it’s not going to be that much different than tonight), go take a peek at the supermoon. It’s there just for you!