Because of the elliptical shape of the Moon’s orbit, its distance from the Earth is constantly changing. This week – Monday, November 14, 2016 – we will have a Full Moon which will be at its closest since 1948. Since it is closer than usual, it will appear larger than usual. Hence, the name, supermoon.
The supermoon has gotten a lot of publicity, although the event will not be very exciting. The visual size difference between the Moon at its closest and the Moon at its farthest is about 14%. If we could view both the “large” Moon and the “small” Moon at the same time, a 14% difference would be obvious. Unfortunately, the Moon doesn’t present itself that way. So, we need some way to measure the Moon’s apparent diameter, so we can compare it with a future sighting. I have added some links to articles on this topic.
In my humble opinion, the easy ways of measuring the Moon’s apparent diameter are not very accurate. However, if you have a camera which can make a large, sharp image of the Moon, try taking pictures this Monday and compare them to future pictures. Of course, you would need to use the same settings for all the images. This would be fairly easy, and fairly accurate.
Another technique would be to take a good look at the supermoon, and examine the finest possible details of it’s surface. Make a sketch or make a mental note of what you could see. Repeat this exercise next month.
My plan is to simply go out and take a good look at the supermoon, and call it a night.
Here are some links to more information:
http://www.skyandtelescope.com/observing/see-the-biggest-supermoon-in-68-years/
http://www.astronomy.com/observing/news/2016/11/theres-super-hype-for-this-months-super-moon
Real Simple Astronomy 
Leave a comment