Posted: Mon Sep 28, 2015 12:28 am
Tonight those of you residing on the other side of the world are, I hope, enjoying an eclipse of the moon. Since the moon is at perigee, its closest approach to the earth, it appears larger and brighter than usual when it is full. Perigee is from Greek, peri, near, and ge, earth. The reddish hue bathing the full moon ("bloody moon") during the eclipse is caused by the same atmospheric effects that make our earthly sunsets (and sunrises) reddish: the bending of the sun's rays as they pass through the earth's atmosphere so that the warm end of the spectrum reaches our eyes or is reflected back to our eyes from the full moon.