- Posted August 9, 2014 by
Santa Cruz, CA, California
This iReport is part of an assignment:
Summer of the supermoons
Supermoon and Meteor Shower as Summer Lunar Marathon Continues
Each month, the moon has a point in its 27.5-day orbit where it’s closest to Earth, called perigee. But, for it to be an actual supermoon, that perigee needs to coincide with a full or new moon. Supermoons are known as perigean new moons or perigean full moons.
Sunday, August 10th, will host the biggest and brightest supermoon of the entire year, which is more than just a perigean full moon due to being the closest one to Earth this year, and earns the title by astronomers as a proxigee full moon. It will pass at a distance of approximately 221,765 miles from Earth, according to the EarthSky website at earthsky.org. It will be noticeably bigger and brighter to the eye, but only if you are paying attention.
The annual Perseid meteor shower begins to peak on Sunday for the northern hemisphere as well, but might be outshone by the full moon. The peak viewing nights for the Perseid showers are between August 10th and 13th. Some astronomers have recommended trying to view them in the hours before dawn. But even though visibility might be a bit obscured by the light of the moon, you should still be able to see some, so don’t let that stop you from trying.
“Supermoon” is not a scientific term. It was most likely coined about 30 years by an astrologer, not an astronomer, named Richard Noelle. However, the term is being used more today by scientists and the public to help describe these normal lunar events.
Three supermoons have already occurred this year, with two in January and one in July. The two January occurrences happened during new moons, so they weren’t visible by looking at the moon. But, the effects could still be witnessed by the higher and lower than average ocean tides, known as perigean spring tides, or king tides. However, this summer, the three supermoons are all during a full moon and can be witnessed by the eye.
What is a king tide then, and what does this have to do with a supermoon?
The oceans are affected by the moon’s gravitational pull, and a full moon brings a higher and lower tide during each lunar cycle, every month. These tides are known as spring tides. But, during a supermoon these tides are more extreme causing a perigean spring tide, or king tide.
The highest perigean spring tide of the entire year is often what is referred to as the actual “king tide”, but the name seems to be catching on to describe these tides during any supermoon.
During the winter or storm seasons, the king tides are more dramatic and can cause some local flooding if they happen during a storm, but generally the difference is not big enough to cause any issues, and it is just a fun thing to witness if you are near the ocean. The lowest tide can be especially fun to explore because you get to experience tide pools and other areas that are normally underwater.
Some people might worry about all this. However, no need for worry, this is a natural occurrence that has been happening all along, it has just been in the past number of years where it has been really brought to the public spotlight, so relax and just enjoy.
Check out your local tide tables to find out when the low and high tides will occur, as the times vary with location. Also, both high and low tides occur twice a day. You might want to plan on getting there an hour or two beforehand, so you can experience it while it is happening.
September will bring another supermoon, though not as close as the one in August, it will still be fun to witness. We can actually have several supermoons in one year, but we don’t always get five. According to the EarthSky website, in 2017 we won’t even have one!
So get out, and have some fun! Don’t forget to look up in the northeast part of the sky for the meteor shower, too. You also might want to take some photos and share them with #supermoon2014 or #supermoon on your favorite social media site.