Wednesday, June 26, 2013
June 23 will have the biggest brightest full moon of the year.
The moon’s orbit about Earth is elliptical, so its distance from the Earth changes with its position in orbit. The closest approach in its orbit to Earth is called its “perigee” point; the moon orbits Earth once every 28 days, so there are about 13 times a year when the moon is at its perigee. The difference between the visual appearance of the size of the moon is about 13% between its perigee and apogee, when its orbit places it at its furthest point from Earth. But due to that elliptical orbit, the perigee point varies just a bit from month to month, and this year, the full moon of June (which rhymes with spoon) will be the closest perigee for the year.
AND – added benefit, this perigee corresponds to a full moon. Perigees are not tied into the phases of the moon: there could be a perigee when the moon is waxing, waning, half-full or simply there, hiding behind a cloud. This year, the perigee coincides with a full moon, all the better for werewolves!
The Supermoon phenomenon seems to have been hyped over the internet, and many will want to go outdoors and see something really wonderful, akin to the photo with this post. However, the size of the moon will only be about 1% larger than the smallest full moon of the year, and this is not enough to make out simply by looking at the moon and trying to remember what it looked like last month. Will this lunar proximity of the moon influence tides? Yes, but then, it always does at perigee.
If you see the moon on the horizon, it also might look bigger than you remember it because of something called the “moon illusion.” There are two reasons given for the moon illusion: one is that your brain “sees” the moon as larger when it’s compared to foreground objects; the other is the magnification of the moon by a phenomena called “atmosphere lensing” that, because the light passing through hotter or colder or vapor-bearing air masses. The photo with this post by Chris Kotsiopoulos (that’s the Temple of Poseidon at Sounion in the foreground) proves that the moon always looks bigger here in Greece.
You, too, could try taking a photo of the Supermoon, but it probably won’t look very super. The “secret” for taking a huge moon photo has nothing to do with waiting for the occurrence of a Supermoon, but the camera lens used to take it. For a huge moon, the lens should be huge, 200 mm or more. And the tripod must be steady, and the atmosphere clear, and and and… from personal experience, good luck!
The moon is always wonderful to look at. Whether “super” or not. Particularly when full on a summer evening in June. And I hope you do go this evening to look at it together with your “significant other” and enjoy it tremendously!
Sorry for being late in post;
Photo used by permission (thank you, Chris) of Chris Kotsiopoulos at www.greeksky.gr
Further Supermoon sources:
blogs/bad_astronomy/2013/ 06/20/ supermoon_big_bright_moon_b ut_no_more_than_usual.html