Moon Question of the Day


Why does the Moon look so much bigger on the horizon than it does once it has risen higher in the sky?

When the Moon is on the horizon, you have other objects, such as houses and trees, to compare it to, so it looks larger. Once the Moon is in the sky, the only things to compare it to are the stars, which appear as tiny points of light. Hence the Moon looks smaller once it has risen.

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Last 7 Days

Is the temperature colder during a full Moon?

Air temperature is not affected by Moon phase. It is affected by the season and whether there is a cloud cover, among other things. On a clear night, heat rises from Earth if there is no cloud cover holding it in. This might make you think it's colder because there is a full Moon, but it's really colder just because the sky is clear.

On December 26, 1978, the Moon had a star resting on its tip. What was this called and how often does it happen?

In the morning hours of December 26, 1978, Venus was totally obscured by the Moon, depending upon where you were standing. From some angles, it appeared the planet was resting on the Moon. Such a phenomena is called a "lunar occultation."

What have our astronauts left behind on the surface of the Moon?

Well, there's quite an inventory. Of course, there's the American flag, left by the first visitor, Neil Armstrong. The first Apollo landing crew also left a commemorative plaque. The remains of seven unmanned lunar probes, Surveyors 1 through 7, are there, plus three lunar rovers. There are six long-term scientific stations on the Moon, which include seismometers to measure tremors in the Moon's crust and some reflectors to bounce back light beams that we send up there. The Russians left several unmanned probes and assorted lunar rovers on the Moon as well.

When does a new Moon rise?

The new Moon always rises at sunrise. The full Moon always rises at sunset.

I've heard that if you cut your hair on a full Moon, your hair grows healthier and faster. Is this true?

According to folklore, if hair is cut during the Moon's waxing phase (between new and full), growth is encouraged. The opposite will occur if hair is cut during the waning phase (the day after the Moon is full to the day before it's new).

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.

What is the most recent year that had a full Moon on February 29?

This occurred most recently in 1972. This is indeed a rare event, since the next most recent year was 1820.

Is it true that when the Moon is tipped on its side, it is going to rain or snow?

According to folklore, if the new crescent Moon holds its points upward, able to contain water, you can expect a dry spell. If it stands on its points, expect precipitation to spill out.

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.

I was told about a documented case in which onlookers saw a blood-red Moon and stars falling from the sky. Where might I find this piece of documentation?

Astronomically speaking, it is possible to observe a "bloody" Moon during a lunar eclipse, when Earth's shadow casts a dark reddish color on the Moon. And, indeed, stars often appear to "fall" from the sky. But we think that what you have in mind is not an astronomically documented case but a quote from the Bible, specifically from Revelation (6:12-13): "And the sun became black as sackcloth of hair, and the moon became as blood; And the stars of heaven fell unto the earth, even as a fig tree casteth her untimely figs, when she is shaken of a mighty wind."

Why did the old almanacs always recommend planting potatoes on Good Friday?

We can't speak for other old almanacs, but certainly The Old Farmer's Almanac has never recommended planting potatoes on Good Friday; our only recommendation has been to plant by the dark of the Moon. Further, all our research has turned up contrary advice -- neither to plant nor to dig potatoes on Good Friday. It was thought the timing would produce poor crops. The Creoles of Louisiana believed that if the ground were cut open on this day, Christ's blood would run out into the rows. The only exception we found was an old belief that seeds planted on Good Friday will thrive.

Is there such a thing as "Moon weather"?

Country wisdom says that the full Moon brings frosts in spring and fall and periods of extreme cold in winter. Researchers have found a striking correlation between the full Moon and cloudiness, rainfall and thunderstorms.

What is the temperature on the Moon?

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

Why don't eclipses occur every month?

If the Moon always moved on exactly the same path, and if that path crossed in front of the Sun, there would indeed be an eclipse every month--two of them, in fact, one of the Sun and one of the Moon. But the Moon's path is more complicated than that, and most months it passes above or below the Sun.

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