Starship Asterisk*

Hello!

I captured this particular image last week:
http://www.flickr.com/photos/ifringe/4175565814/

The exact time/location is noted on the photo. I was facing almost due west at the time of capture, and the rays lasted only a moment. I initially thought it was some sort of green flash, but a friend commented that perhaps they are Crepuscular Rays?

So... is this indeed what they are?
Thank you very much!
david

ifringe wrote:I captured this particular image last week:
http://www.flickr.com/photos/ifringe/4175565814/

The exact time/location is noted on the photo. I was facing almost due west at the time of capture, and the rays lasted only a moment. I initially thought it was some sort of green flash, but a friend commented that perhaps they are Crepuscular Rays?

Yes, that's basically correct. I'd make a distinction between crepuscular rays, which are bright against the background sky, and crepuscular shadows which are dark against the sky. Your image shows shadows. Rays occur when the Sun is setting behind clouds or mountains that are dense enough to only let a little light through; shadows occur when it is setting mostly in the clear, with only an occasional cloud or mountain peak to cast a shadow. But either phenomenon is often simply called "crepuscular rays".

Thank you so much, Chris, for the great information/explanation.

I've edited up the Flickr page to now have the correct information.

Thank you!
david

A blue flash... maybe on Mars? I've heard it has blue sunsets. Perhaps it would have a purple flash, then. Or maybe Mars does not enjoy flashes at all.

geckzilla wrote:A blue flash... maybe on Mars? I've heard it has blue sunsets. Perhaps it would have a purple flash, then. Or maybe Mars does not enjoy flashes at all.

Any colored flash as the Sun rises or sets requires significant atmospheric refraction and dispersion. It isn't clear that the atmosphere on Mars is dense enough to bend the light path sufficiently to produce a visual green (or blue) flash.