Monday, June 22, 2009

Sunset Solstices
This panorama consists of three separate images from the VMNH Weatherbug webcam stitched together using Microsoft Digital Image Suite. The leftmost image was taken at sunset on the 2008 winter solstice, December 21, 2008 at 5:07 pm. The image on the right was taken just before sunset on 2009 summer solstice, June 21, 2009 at 8:34 pm. What this shows is the distance from the southernmost sunset to the northernmost sunset for our latitude (36.68 degrees north). Over the next 179 days, the sunset will make its way southward again until it reaches the same spot it was last year and will "stop" (solstice is Latin for "sun stand still") and begin its journey northward. This apparent motion of the sun is caused by a combination of the tilt of the earth's axis (about 23.5 degrees) and the earth's revolution around the sun. Click on the image to enlarge.