Earthlight or earthshine on the moon.
earthshine definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
the faint illumination of the dark part of the moon by sunlight reflected from the earth
earthshine definition by American Heritage Dictionary
The sunlight reflected from the earth's surface that illuminates part of the moon not directly lighted by the sun. Also called earthlight.