Week of June 19-25, 2016
As the sun disappears from view behind the western horizon on the evenings of Sunday June 19 and Monday June 20, face the opposite direction and you'll soon see the full moon rising.
Which is the night of the actual full moon? Well, since the moon reaches its official full phase at 7:02 a.m. on June 20 on the U.S. East Coast, and 4:02 a.m. on the West Coast), you can expect the moon to appear full on the night before, June 19, and the night of.
And since June 20 also marks the summer solstice — the first day of summer in the Earth's Northern Hemisphere — the day provides a good opportunity to check out the movements of the sun and moon across our sky.
Beginning stargazers often have a tough time following the movements of the moon. That's to be expected, because the moon's orbital motion around the Earth, coupled with the Earth's rotation, makes it rather difficult to follow.
The trick is not to try to grasp the complexities of its roughly 28-day cycle but rather to break down its motion into phases. Simply choose one phase of the moon cycle and try to understand, or even predict, how its position will change over time.
For example, let's imagine the full moon. Since the full moon occurs when the moon is fully lit by the sun, it always lies on the opposite side of the sky than the sun. We would expect, therefore, that it also behaves in a manner completely opposite the sun. And it does. When the sun sets, the full moon rises; when the sun rises, the full moon sets.
During summertime in the Northern Hemisphere, when the afternoon sun dips below the northwestern horizon, the full moon is rising in the southeast. The sun rides high across the daytime sky, and its light shines more directly toward Earth, giving rise to higher temperatures. Because the full moon always behaves contrarily to the sun, you can expect it to ride low across the nighttime sky and set in the southwest. And, because the summertime full moon never appears very high, its light must pass through a thicker column of atmosphere, which can give it a rather dusky glow.
Of course, during wintertime in the Northern Hemisphere, the entire scenario is reversed. The winter sun rises in the southeast and rides low across our daytime sky. Its low path contributes to lower temperatures. The full moon rises in the northeast at sunset and arches high across the nighttime sky. During this time, its light passes through much less atmosphere and therefore shines brilliantly all night long.
During the course of an entire year, you'll notice that the full moon swings north and south along the eastern horizon as it rises — just as the sun does during its morning rise, except that the full moon will appear opposite of wherever the sun appeared that morning.
Stick with one particular phase, and watch it carefully from month to month. It may take awhile, but you'll eventually learn to predict just when and where the moon will appear.
Visit Dennis Mammana at www.dennismammana.com. To read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.
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