Thursday, November 30, 2017

Another Supermoon!

Here's how the December 3rd "Supermoon" compares with the previous four full moons. For me, any phase or position of the moon in the sky is worth observing or photographing, but so-called "supermoons" and "micromoons" aren't that special or noticeable from other full moons. Chances are if you hadn't read anything online or heard anything on the radio, you'd not notice anything particularly different about the upcoming full moon.

The way the media spins supermoon hype is by telling us it will be 14 percent larger than when it's apogee (furthest away from earth). The problem is that most full moons throughout the year are not at apogee. The moon's elliptical orbit has an average eccentricity of 0.0549.  When the moon is at perigee, it's appropriately 223,000 miles from earth. At apogee it's around 252,000 miles distant. On average, the moon is 238,000 miles from our planet. Even for a celestial object that's about the size of the width of the United States, perceived fluctuation in size from one month to another is negligible.

Try this. Click on the above image and stand far enough away from your screen so when you hold out your arm and pretend to pinch the moon with your fingers any disc is roughly the size of a pea. That's actually how large the full moon appears in the sky with the naked eye.

Ignore the hype! Just watch the moon whenever you feel like it.

Moon image © 2017 Mike McDowell

No comments:

Post a Comment