Crepuscular rays occur when objects such as mountain peaks or clouds partially shadow the sun’s rays. The name crepuscular means “relating to twilight” and these rays are observed at sunrise and sunset. Crepuscular rays appear to diverge outward from the setting sun, and are visible only when the atmosphere contains enough haze or dust particles so that sunlight in unshadowed areas can be scattered toward the observer.
The light rays are actually parallel, but appear to converge to the sun due to “perspective”, the same visual effect that makes parallel railroad tracks appear to converge in the distance. Crepuscular rays are often red or yellow in appearance because blue light from the sun is selectively scattered out of the beam by air molecules.
I live about 15 miles WSW of Tampa and crepuscular rays are a common occurrence. I suspect that what is causing them here are the buildings in downtown Tampa to the east in conjunction with the “flatness” of Florida. I’ve been observing them for years about 1/2 hour before sunrise and have never really considered them uncommon phenomena. It will be interesting over the next few days to see if they appear in the same configuration. If so then they are not caused by clouds… and CERTAINLY not by mountains. 😉
I was fortunate enough to pick up an Orion 10-inch SkyQuest Dob, Orion 9 and 25 mm plössls, a Celestron 3.6mm plössl, and an Orion DeepView 35mm multi-coated lens for a measly $200 at a “we’re getting divorced get this the hell out of our house” sale.
Needs a little cleaning up but it’s all in GREAT shape! Now if I could only get first light for the brand new ETX125 AT I got for $200 two years ago at a clearance sale, I’d be happy!
Over the years of neglect endured by my blog’s software engine (if it ain’t broke right?) somehow my blogroll and all my links stopped appearing on my site. Apparently my software was so out of date that the original db calls we no longer supported!
Anyhoo, I’ve rectified this and verified/updated all my links. I hope nobody thought I had just deleted them from my blogroll… no one even told me. 😛
I grabbed the camcorder last night and went out to watch the launch of NASA’s Kepler Telescope from my front yard located about 150 miles west-southwest of the Cape Canaveral. To my eyes the engine glow was quite red (atmospheric effect?). It was very clear and dark so there is nothing in the way of skyglow to put the image in perspective. I zoomed out and fiddled with the gamma a bit to try and give some.
At any rate, here it is. This was definitely one of those launches that looked ALOT better to the maked eye from my location and didn’t transfer well to video.
