Moon’s Magic May Play Tricks On You Tonight

The Full Wolf Moon rises in the company of many of winter's brightest stars tonight. Maps created with Stellarium

Aahwhoooooooooooooooooooooooo … aahwhooooooooooooooooooooooo!

Tonight is the Full Wolf Moon, named by the early Native Americans from hearing wolves howl on the long, cold nights of January. Wolves howl at all times of year, but I can attest that their long, lonely calls are heard best in winter, when no other sounds compete for our attention. I recall several subzero nights when it seemed the only warm-blooded animals out under the stars were me and a wolf calling away in the distance. At those times, you’re happy to have the company of a brother mammal.

Wolf at the Wildlife Science Center in Forest Lake, Minn. Credit: AP/Dawn Villella

While the image of a wolf howling at the moon is a familiar one,  I’d guess more people howl at the moon than wolves. According to Fred Harrington, professor of ethology at Mount Saint Vincent University, Nova Scotia, wolves may be more active at full moon, but they’d be wasting their breath. Wolves howl to communicate with their pack and warn wolves from other packs to stay away. It takes energy to howl – nature’s creatures use their resources wisely.

For the Duluth region, the moon will rise at 5:03 p.m. CST this evening in the northeastern sky in the constellation Cancer the Crab. If you’re able to see right down to the horizon in that direction, it’s a kick to watch the moon come up. The thickness of the air in the lower part of the atmosphere absorbs the blue end of the rainbow spectrum. Sans the blues, the moon comes up orange as a cantaloupe. Air also acts like a lens and bends or refracts the moon, distorting its shape. Because the air at the horizon is thicker and denser than that a fraction of a degree higher up, the bottom half of the moon is refracted more strongly than the top half. The result: the bottom is “pushed up” into the top making the moon look squished or oval.

Does the top line look longer than the bottom? Since we think the top yellow line is the same size but farther away than the bottom line, our brain thinks the top line must be larger. Credit: Dr. Tony Phillips

A rising or setting full moon also appears much larger than when viewed higher up, despite the fact that its size doesn’t physically change. This is the familiar moon illusion. When you look at the moon near the horizon, it’s usually accompanied by a familiar landscape of distant trees, buildings, hills and the like. These cues are absent from our gaze when the moon is high up and surrounded by little more than empty sky.

There are several explanations for the apparent difference in the moon’s size (including the Ponzo illusion shown at left), but they all have to do with cues we get from our surroundings that help us determine the distance and size of an object. I invite you to check out the following sites for the fascinating psychological and biological reasons we can’t help our brains from doing what they do:

* The Ponzo Illusion and the Moon
* Explaining the Moon Illusion
* The Moon Illusion Explained

Those of you who aren’t able to watch the moonrise but still have clear skies might catch its shining face in the east on your way home from work or school tonight. Later, around 8 or 9 o’clock, the airless orb will shine like a hard, white diamond in the south.

The full moon is up all night. Watch for it in the west tomorrow morning.

The full moon is 180 degrees opposite the sun and rises around the time of sunset. Naturally then, we should expect it to set around the time of sunrise. I encourage you to visit with the moon both in the evening and again in the morning if your schedule allows. Look for it low in the western sky before sunrise. Whenever I see it before breakfast, I get the feeling it’s been working the night shift, keeping the forest and fields lit for the wolves and owls, helping them find the prey they need to survive.

4 Responses

  1. Pingback : Tweets that mention Moon’s magic may trick you tonight | Astro Bob -- Topsy.com

  2. Kathleen

    Your written was a wonderful pic for today is rain clouds all through the night. My best view area is Pound Ridge Indian Reservation and my twitter follow. Thank you

    1. astrobob

      Thank you Kathleen. Sorry to hear you’ve got bad weather! Happens all the time here, too. We may be clear tonight for a change. If it’s cloudy, go out tomorrow. The moon will still be nearly full but rise about an hour later.

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