Moon Question of the Day

Exactly how long is a lunar month?

The Moon's synodic period (the length of a lunar month) is 29.53059 days -- or 29 days, 12 hours, 44 minutes, and 2.8 seconds.

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Who were the Roman and Greek goddesses of the Moon and the sea?

Diana was the Roman goddess of the Moon. She was a "multipurpose" goddess, presiding over the hunt and childbirth, among other things. In her incarnation as Moon goddess, she was known as Luna. Artemis was the Greek goddess of the Moon. Gods, not goddesses, ruled the sea -- Neptune in Roman mythology and Poseidon in Greek.

What do the phrases "Moon rides high" and "Moon runs low" in the Almanac mean?

As the equator wraps around Earth, so the celestial equator wraps around the sky. It runs in an arc from east to west, passing low in the south; the farther north one stands, the lower it passes. When the Moon runs low in the sky, it is the farthest beneath this equator. If you live sufficiently far north, it will never rise above the horizon at night. Similarly, the Moon will be unusually high in the sky when it rides high.

Exactly how long is a lunar month?

The Moon's synodic period (the length of a lunar month) is 29.53059 days -- or 29 days, 12 hours, 44 minutes, and 2.8 seconds.

According to the Moon, when should you cut your hair to make it grow faster?

During the waxing phase -- that is, when the Moon is between new and full.

What is the temperature on the Moon?

Daytime temperature is about 235 degrees F. Nighttime temperatures can drop to -275 degrees F.

What does neaped mean in reference to a ship?

A boat that is neaped has gone aground on a mild tide and needs a spring tide or stormy waters to float it off. The boat is only barely aground, as opposed to being hard aground, where even a very high tide or rough waters might not be enough to set it free. The expression comes from the term "neap tide," which is a moderate tide. Neap tides occur when Earth, Moon, and Sun are in quadrature. In other words, instead of being lined up in a straight line, as at syzygy, they are more nearly at right angles. True quadrature happens at regular intervals, about twice a month, at the first quarter and last quarter Moons, but neap tides occur for several days around those dates. Take a look at the tides on the right-hand calendar pages of The Old Farmer's Almanac, and you'll notice that high tides are considerably higher around the full Moon and new Moon than around the first and last quarters.

I've heard that on May 19, 1780, in the northeastern part of North America, there was a period of "extraordinary darkness," which began between 10 A.M. and 11 A.M. and lasted until the middle of the next night. Also, the full moon rose at 9 P.M. that evening but was not visible until midnight, when it had the "appearance of blood." I've checked records of solar and lunar eclipses for that date, and none was close enough to have caused the phenomenon. Do you have any information about such an event? Could you provide an explanation for it?

For a generation of New Englanders, Friday, May 19, 1780, was a date never to be forgotten. The Sun was blotted out by a strange darkness, varying in intensity and length from place to place, but extending from New Jersey and New York across Connecticut, Rhode Island, Massachusetts, and southeastern New Hampshire into Maine. For several days prior to the "Dark Day," the Sun was obscured by smoky clouds, and the Moon took on an unusual reddish color. Darkness began around 10 in the morning and lasted throughout the day. (When the Connecticut legislature proposed adjournment following the belief that the day of judgment was at hand, a Colonel Davenport declared: "I am against an adjournment. The day of judgment is either approaching, or it is not. If it is not, there is no cause for an adjournment; if it is, I choose to be found doing my duty.") The night that followed was no comfort to the fearful, being unusually black and impervious to any artificial light. The next day, a fine sulfurlike substance was noticed on the edges of water, but the only reports of adverse effects concerned the death of a number of birds. The first theories of a comet or solar eclipse were ruled out, and the earliest guesses regarding smoke from forest fires turned out to be accurate. Out-of-control forest fires, extending from New Hampshire into New York State, burned furiously for a week preceding the dark day, creating great suffocating clouds of smoke. An unusual atmospheric condition trapped the smoke until it reached sufficient density to blot out the Sun. However, for many New Englanders, the Dark Day was an inexplicable mystery, never recalled without a feeling of awe.

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