This is the launch plume from the recent shuttle launch STS-131 Discovery just before sunrise. I of course missed what was a freaking amazing launch from my vantage point in the Tampa Bay area but about 30 minutes after the launch I went outside and saw this. It’s amazing how the upper level winds distort rocket exhaust and how long it lasts on some occasions. It was an amazing sight in the rising sun.
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 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.