On September 27, 2015, an ominous, blood-red moon shone through the night sky across the globe. This rare occurrence was appropriately deemed the “Super Blood Moon”.

The proper astrology term for this phenomenon is a perigee lunar eclipse. The blood moon results from two astrological moon phases; the first is a supermoon. The moon revolves around the Earth in an ellipse rather than a perfect circle, and a supermoon occurs when the moon is closest to the Earth, or at its perigee, appearing up to 14% larger from Earth. Lunar eclipses occur when a full moon passes directly behind Earth’s shadow (AKA umbra). Here at its perigee the moon also directly passes behind Earth’s immense shadow, causing a red-tinted monstrous moon to becomes visible in the night sky.

These super moon lunar eclipses occur about every 18 years, 11 days, and 8 hours. This super blood moon has only occurred five times since 1910, the last time in 1982, and it will not appear again for another 18 years.

The Internet had ambivalent feelings about this rare event. Some people had a perfect view of the spectacular red moon and reported it as an astonishing sight, while others were not so lucky, as most were asleep when the blood moon rose. The more vigilant star gazers, unfortunately, saw clouds block this infrequent lifetime experience. San Francisco can safely blame Karl The Fog for blocking its view. Luckily, we get another opportunity to see the blood-red moon again, hopefully, in 2033.