A cosmic phenomenon occurred early morning on Tuesday, April 21^st between the hours of two o’clock and five o’clock A.M. In this galactic display, the sun, the earth, and the moon all aligned in such a manner that the full moon orbited entirely behind the darkest part of Earth’s shadow, known as the umbra. As a result, the moon turned a deep sunset red, to which the name, “blood moon” was given. This celestial spectacle is known as a total lunar eclipse.

How does this “bloody” color occur? Humans observe the moon to be a sphere with a white surface because it reflects the sun’s light, even though the moon has no light of its own. During a lunar eclipse, one would assume that since the earth shields the moon from the sun’s rays, the moon would be black.

However, the sun’s light still passes through the earth’s atmosphere, and while the earth’s atmosphere absorbs and filters out the blue light waves, reddish-orange light passes through earth’s atmosphere to the moon along with sunlight refracted by the earth to illuminate the “blood moon”.

Lunar eclipses often occur twice a year, but what makes this particular eclipse so extraordinary is that the moon passed completely behind the core of the earth, causing a total eclipse moon and resulted in the full “blood moon” that was observed on Tuesday.

Even more extraordinarily, this eclipse was the first of four consecutive total lunar eclipses, which will take place in the next two years. (There will be six-month gaps in between each eclipse.) This series is known as a “tetrad” and the next three eclipses will take place in October 2014, April 2015, and September 2015.

Luckily, these eclipses will all be visible from the United States, weather provided. Storm clouds can obstruct the view of the eclipse, as was the case with the eclipse on Tuesday as a result of ominous clouds roving through the skies of Albany, New York.

Did you miss the lunar eclipse because of these clouds? Or perhaps you didn’t wake up early enough? Maybe you didn’t even know that the lunar eclipse was occurring! Not to worry, now you know, and you can see the next blood moon, which will be visible on October 8, 2014 – a marvel worth watching.

For more information, you can visit www.nasa.gov or follow @NASA on Twitter.