What in the world is a lunar eclipse tetrad?
On April 15, 2014, an extraordinary series of total lunar eclipses will begin in the United States. This series, called a lunar eclipse tetrad, will result in four red moons over the course of a year and a half. NASA explains the significance behind this phenomenon, and sheds light on how the moon transforms into a bright red orb.
Additional Resources for you to Explore
Check out NASA's own eclipse website for more info on the coming tetrad.For more info on what causes the phases of the moon, check out this video by Veratasium. The phases of the moon are actually just a result of our perception of the moon's half-illuminated surface. When the moon does pass through Earth's shadow the result is a lunar eclipse. This can be spectacular as the moon turns a deep shade of red.Want more fun facts about the moon? Have you ever noticed how a full moon looks bigger on the horizon than high overhead? Actually, the two images are exactly the same size -- so why do we perceive them differently? Andrew Vanden Heuvel unravels the details of focus, distance and proportion that contribute to this mystifying optical illusion.