Moon Question of the Day

How old is the Moon?

The Moon is approximately 4.6 billion years old.

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Last 7 Days

Why is there a crescent Moon cutout in outhouse doors?

We don't know whether the crescent Moon was the standard cutout in every outhouse door in the country, but it's certainly the embellishment of choice for artists and illustrators. Such an opening may have been chosen because (1) it provided some ventilation and illumination and (2) it afforded a modicum of privacy for the occupant.

Does the Moon rise and set in any particular time pattern?

The rising and setting of the Moon is retarded from day to day, but the delay is not consistent. At moonrise, the Moon occupies a particular place in the celestial sphere. Approximately 24 hours later, the Moon has moved to the east in the sphere, so moonrise and moonset occur a little later. In the northern United States, the daily delay can vary from a few minutes to well over an hour.

How old is the Moon?

The Moon is approximately 4.6 billion years old.

I am interested in any folklore concerning marriage and the Moon.

The ancient Greeks believed that marriages consummated during the full Moon were the most prosperous and happiest, but a waning Moon boded ill for wedded bliss. The full Moon is also considered to be an ideal time to accept a marriage proposal. Folklore has it that if a young woman sees a dove and the new Moon at the same instant, she should say, "Bright Moon, clear Moon, / Bright and fair, / Lift up your right foot, / There'll be a hair." When she removes her shoe, she'll find a hair that is the same color as her future husband's.

How did the special names that we give some of the Moons, such as the Hunter's Moon, begin?

Historically, the Native Americans of the northern and eastern United States kept track of the seasons by giving a distinctive name to each full Moon. With some variation, the same names were used throughout the Algonquin tribes from New England to Lake Superior. These remain the full Moon names we use today.

Are there any ancient cultures known to have had a Copernican model of the solar system?

We can't find any record of a culture that believed the Sun was the center of the universe, but Copernicus wasn't the first person to say this. Around 270 B.C., on Samos (an island off the coast of what is now Turkey), Aristarchus put forth a theory of a sun-centered universe, which included his belief that the Moon's light came from the Sun. He is sometimes referred to as the Copernicus of antiquity.

How come longitude lines start in Greenwich, England?

The Royal Observatory Greenwich is located at the National Maritime Museum in London. The original site of the observatory was arbitrarily chosen as longitude 0 degrees in 1884. A plaque in the original structure marks the zero point from which longitude is calculated. The observatory was founded in 1675 by King Charles II to keep accurate tables of the position of the Moon for the calculation of longitude by English ships. In 1750 those tables were published as the Astronomical Observations, and after 1838 they were published annually. Meridian observations of the Sun, stars, and planets also were made at the observatory. Photographs of the Sun were taken daily, conditions permitting, and a continuous photographic record of sunspots was kept starting in 1873. Today the observatory is primarily a museum with a small planetarium.

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