Turn your gaze to the stars tonight for an eerie and spectacular view of the "blood moon." At 12:53 a.m. ET, the Earth will begin to position itself between the sun and the moon for the first of a series of four total eclipses to conclude in September 2015.
The phenomenon is known as a tetrad, in which the moon is completely covered by the earth's umbral shadow for four eclipses in a row, as opposed to only partial eclipses that fall in the outer penumbra. But rather than succumbing to complete darkness, the moon will glow red as it receives the refracted light that spills over the Earth's circumference.
The series is a rare occurrence in history, with large spans of time, such as the 300 years between 1600 and 1900, witnessing none. But the 21st century will be more promising, according to Fred Espenak, who works for NASA's Goddard Space Flight Center and specializes in eclipse predictions.
"Frequency sort of goes through 585-year cycles," the astrophysicist explains. "So you go through centuries where you don’t have any, and centuries where you have a number of them."
The next tetrad will begin in 2032.
Other factors add to the singularity of this year’s event. For one, North America will have front-row seats to the show, not always a guarantee. It just so happens that this part of the western hemisphere, along with some of South America, will align perfectly with the cast shadow. The rest of the world, on the other hand, will experience partial visibility or none at all.
But while the event is sure to be a breathtaking sight, for some it signals a certain foreboding. "Something is about to change," Pastor John Hagee of the Cornerstone Church in San Antonio, Texas, writes in his newest book on the four blood moons.
Because many biblical references cite the celestial bodies, Hagee says, "God uses the sun, moon and stars to send signals to us on the earth."
Among his most inspirational verses is Joel 2:30-31: "And I will show wonders in the heavens ... the sun shall be turned into darkness and the moon into blood before the coming of the great and awesome day of The Lord."
To catch the moon at its bloodiest (with the naked eye but weather permitting), spectators should look up at 3:07 a.m. when it is entirely covered by the earth's shadow.
- Space & Astronomy