On Saturday, March 19, the moon will be what has been called a “supermoon”. This means that the moon will be at its closest to Earth (at “perigee”, which occurs about every 413 days), and it will also be full—one of the two times a month when Earth, moon and sun are aligned. Actually, the full moon and the moon at perigee occur within about an hour of each other on the 19th, which some say make it a super supermoon.
You shouldn’t be too alarmed about that “closest to Earth” phrase; on Saturday the moon will pass by about 17,433 miles closer to us than its average distance of 239,000 miles. That’s a wee bit over 7% closer, and isn’t all that rare. But maybe it will look a little larger than usual this time, and that’s worth hanging around to see.
It has also been said that this super supermoon was influential (even causal) of the devastating earthquake and tsunami that hit Japan on March 11. That is patently not true. On the 11th the moon was actually at a right angle to Earth, and therefore was exerting its least influence on our planet.
What a full moon at or near perigee does do, however, is cause very high tides. Should a significant storm move through a coastal area during a supermoon event, flooding is possible and that’s worth paying attention to, too.
I love the moon, and even though I may not really be able to see that 7% difference, I’m looking foward to seeing a lovely near-full moon tomorrow night, when our skies might be clear. By Saturday we’ll be clouded over again, so I’ll take my view when I can.
Whether I can see a difference or not, I like the idea of knowing that I’ll be looking at a super supermoon—which won’t happen again until November 14, 2016.