Friday, December 11, 2009

Skywatch: Mystery Clouds

Last week, before the onslaught of dense clouds and cold weather we've been having, I kept trying to capture a Colorado "true blue" sky. My timing was never right, as the best ones occur in morning hours, off to the northwest, while south and east tend to be more washed out.

Then this unusual formation caught my eye—several broad streaks radiating from an area to the east, behind the hogback, like faint streams of sediment in an otherwise clear stream. The only explanation I can offer is contrails, spread laterally by winds aloft, or what, according to Wikipedia, would be called decaying contrails. This is suggested by comparison with the relatively coherent trail to the right.



A sky without contrails, or artificial clouds, would have been standard not so very long ago. Here's a better view of the hogback, one of my all-time-favorite geographic features, showing the west, or scarp, face of the Dakota Group sandstones that create the ridge.

Posted for Skywatch Friday, where many more skies await you.


9 comments:

JOE TODD said...

Mystery clouds and beautiful sky

Rambling Round said...

Beautiful blue skies capture.

Gwendolyn said...

Blue skies - well enjoy them while you can - our part of the country has grey skies..... Thanks for sharing your pictures and the story behind them.

JOE TODD said...

Thanks for visiting my blog and the comment/link to CCC I also enjoyed visiting some of your other blogs. Am looking forward to future visits. The CCC was involved with several projects in that area

In Three Rivers, Michigan said...

Beautiful blues, with or without jet exhaust. The moon looks lovely. I'm going to look up Dakota Group sandstone now.

Three Rivers Daily Photo

Grace said...

Beautiful blue color sky! So , what is a hogback?
I'll have to look up Dakota Group sandstones, too.
Came to your post to see a bit of Colorado. I have not yet visited any states in the west except Seattle, Tacoma area and all my photos are pre-digital camera times.

Sally said...

Thanks for stopping by, everyone! Nice to meet you...

For those who are looking it up, I'm afraid I confused the issue by calling it "Dakota Group sandstone"-- you'll do better searching for Dakota sandstone. Here's a really good link that will give you a sense of the area. Wikipedia also has entries for Dakota hogback (basically a sharp ridge) and Dakota sandstone.

I'm glad this post stimulated a little interest in geology, guess I'd better deal with these questions sometime soon!

Thanks again!

Kenton and Rebecca Whitman said...

It's interesting that these jet trails can become something so beautiful when seen with a different perspective. And the 'hogback' looks like a fun place to explore!

In Three Rivers, Michigan said...

Thanks for the link -- very interesting!

Three Rivers Daily Photo