Tonight is the Pink Supermoon! And sadly I won’t see it as it will be overcast here in Verbier. But for those of you who do have good weather, you should definitely try and get out and see it. It won’t be pink as the name suggests, this is because it was named by the Native American tribes and colonial settlers in the USA after a pink moss (Phlox Subulata) that blossoms in spring. A Supermoon occurs when the moon is at or near its closest approach to Earth in its orbit. A Supermoon is only about 7% larger and 15% brighter than an average full moon despite it seeming much bigger. 

The Moon Illusion

Have you ever noticed that sometimes when the moon is rising it looks huge, a lot bigger than usual? Well, believe it or not, this is our brain playing tricks on us. Scientists believe it is an optical illusion created when our brain process objects close to the horizon when in proximity to mountains, trees and buildings for example. Then when it is higher in the sky and your brain has nothing to compare it with, it seems smaller again.

Preston Dykes, NASA’a Public Engagement Specialist at their jet propulsion laboratory describes this so well in the short audio clip below. He also describes a small trick that will prove this. '“Hold up your outstretched finger next to the moon. You’ll find that your fingernail and the Moon are about the same size. Or try looking at the Moon through a paper tube or bend over and look backward between your legs. When you view it like this, the moon will be nowhere near as big as it had seemed”.

I find it incredible that the reason for this optical illusion is still under debate. Try the thumbnail trick, it’s quite strange!

Photographers can also create a similar illusion by using a telephoto lens to create lens compression. Focal lengths of above 400mm start help you capture a giant moon. If like me, you are not lucky enough to own a lens above 400mm, then you can use a teleconverter. The only downside is that they can negatively impact the sharpness of a shot. Another option is to rent a lens for a couple of days during the Supermoon. But check the weather first so that you don’t waste your money on renting a lens that you cannot use. On next months full moon I will write up tips and settings for shooting the moon..

The Moon Illusion on NASA: https://solarsystem.nasa.gov/news/1191/the-moon-illusion-why-does-the-moon-look-so-big-sometimes/