Four Days in July
The sequence of images is set up so that the Sun is toward the lower right and the center of our galaxy in the constellation of Sagittarius is to the upper left. This image shows the Earth's orbit during July, when Sagittarius is prominent in the night sky of Earth near midnight. Neither Earth nor Moon is visible except as a point of light -- if you knew where to look. Earth travels around the Sun in this image from right to left at about 2 500 000 km per day, taking four days to cross the image. During that four days, the Moon traverses only 1/7th of its orbit about the Earth. With respect to the Sun, the Moon's path is essentially the same as Earth's with a very slight inward and outward wobble. The diameter of the Sun is 140 000 km so at this scale the Sun would be almost 1 1/2 times the size of the central square.
Copyright © 2016 by Bruce Bryson