Friday, January 29, 2010

A Convenient Ring Around the Moon...

Okay, I had my shot of the Moon and Mars all planned out, rising over the mountains. It was going to be beautiful. And then the clouds were there...

But sometimes the shot you get is not the one you expect. I got a craving for a Sonic chocolate malt around 9:30 and when I stepped outside, there were high, thin clouds but the Moon and Mars were poking through. Better yet, there was a ring around the Moon. Ran back inside, got the camera and tripod, positioned a spooky tree in the shot and...


As usual, click to embiggen. Mars is just to the left of the Moon. To the right and above is Procyon. Pollux is visible at the very top of the image (I cut off Castor). The little greenish splotch right below the Moon is a lens flare caused by internal reflections and scattering in the lens system. And of course there is the nice ring.

Rings such as this are formed by Moonlight interacting with ice crystals in the upper atmosphere. These ice crystals are shaped like hexagons.

So, not quite what I was expecting, but a pleasant surprise tonight.

Reprinted with permission from the Half-Astrophysicist Blog.

1 comment:

kkdither said...

Very cool hale. As always, a great picture. I was lucky enough to see the moon last night through a hole in the clouds for about a minute before it disappeared. Didn't capture a photo. It was just too darn cold out.

By the time it rose above the neighbors house, it was no longer spectacular in size and I would not have been aware of perigee had I not been previously informed.

Remember the movie, Moonstruck, with Cher? I want to see Cosmo's moon...