WRAL WeatherCenter Blog

On the way driving to work this morning I viewed the moon in front of me and the sun behind me. Is there a particular terminology used for this occurance and what is it's significance, if any.

Posted October 22, 2008 10:24 a.m. EDT

MIKE MOSS SAYS:       Lynette,     There isn't an especially great significance to seeing the moon low on the horizon in one direction while the sun is low on the horizon in the other, apart from the fact that this only occurs pretty close to the time of full moon. The reason the moon is full at that time is that it is located almost on the opposite side of the earth from the sun. Of course, if it happens to sweep through the spot that is precisely opposite the sun there will be a lunar eclipse, but dueing most full moons it passes just above or below that spot.

The only word I can think of that pertains to this effect is "syzygy," meaning generically an alignment of three or more celestial bodies. This occurs, at least approximately, with each full moon, since the sun, earth, and moon must be arrayed in a nearly straight line for the moon to appear fully illuminated, and at this time the sun will rise just as the sun sets and vice versa. Another name for this is "outer syzygy," and it happens 12 or 13 times each year.

An alignment of the sun, moon and earth called "inner syzygy," with the moon and sun both on the same side of the earth, leads to the new moon, when the sun and moon both rise and both set at about the same time, and occasionally a solar eclipse occurs.