In the early hours of April 15, 2014, our pale moon will turn blood orange red. This spectacle will mark the first of four consecutive total lunar eclipses, a series known as a tetrad. A lunar eclipse occurs when the moon dips behind Earth’s shadow.
Most eclipses are partial, meaning only portions of the moon are hidden from the sun. But sometimes the moon, Earth, and sun perfectly align so that the entire moon is shielded from the sun’s rays. When this happens, wayward beams of sunlight filter through Earth’s atmosphere, coloring the moon a fiery red, resulting in a total eclipse.
While a tetrad itself isn’t rare, NASA scientists say that its visibility across the entire United States is unique. Watch the video to learn more.