A rare astronomical phenomenon Sunday night created a moon that appeared slightly larger than usual and with a reddish hue, an event known as a super blood moon. It’s a combination of curiosities that hasn’t happened since 1982, and won’t occur again until 2033. A super moon, which occurs when the moon is closest to earth in its orbit, will correspond with a lunar eclipse, leaving the moon in Earth’s shadow. Individually, the two phenomena are not uncommon, but they do not align often.
Celestial events have a long history of producing fear. Stories abound of how this super-moon will be enormous in the sky, that it could trigger earthquakes, that the blood red color is a sign of doom, and the fact that this one is the fourth in a series called a Tetrad must mean some kind of apocalyptic ending.
First, let’s clear up your understanding of the super moon.
The moon’s orbit around the Earth is an ellipse rather than a perfect circle, so the distance to the moon can vary by more than 50,000 kilometers. Last weekend, the moon was at its closest point, so it appeared 30 percent brighter and 14 percent larger than during normal moonlit nights. That may sound like a lot, but that’s 14 percent of something that is very small for the human eye to recognize. But the reddish tint from the lunar eclipse was to be more visible throughout much of North America, especially on the East Coast. “You’re basically seeing all of the sunrises and sunsets across the world, all at once, being reflected off the surface of the moon,” said Dr. Sarah Noble, a program scientist at NASA.
So there is no correlation between super moons and earthquakes, although tides were definitively higher and stronger last weekend. Because the tides are influenced by both the Moon and the Sun, it’s easy to see that when the Sun lines up with the Moon and the Earth, as during a New Moon or Full Moon, the tidal effect is increased. These are known as spring tides, named not for the season, but for the fact that the water “springs” higher into the air than normal.
The key to how the tides work is understanding the relationship between the motion of our planet and the Moon and Sun. As the Earth spins on its own axis, ocean water is kept at equal levels around the planet by the Earth’s gravity pulling inward and centrifugal force pushing outward. However, the Moon’s gravitational forces are strong enough to disrupt this balance by accelerating the water towards the Moon. This causes the water to ‘bulge’ as the Moon orbits our planet and as the Earth rotates, causing bulge to move in relation. The areas of the Earth where the bulging occurs experience high tide, and the other areas are subject to a low tide.
Although this was a beautiful phenomenon to experience, everything has a cause and effect. For me, I was lucky enough to capture a few pictures through breaks in the clouds. Although not as dramatic as some of the photos seen on the news and on the internet, the event was both interesting and memorable.