Red Moon, Green Beam . ... The green beam of light and red lunar disk are real enough, captured in the early morning hours of April 15. ... Immersed in shadow, the eclipsed Moon reflects the dimmed reddened light of all the sunsets and sunrises filtering around the edges of planet Earth, seen in silhouette from a lunar perspective . But the green beam of light really is a laser. ... Conducting the lunar laser ranging experiment during a total eclipse uses the Earth like a cosmic light switch. ...