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Revision as of 12:46, 25 December 2013

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Moon Shapes
Whenever I see a picture of the moon where the points go more than halfway around, I assume it's being eclipsed by one of those Independence Day ships and interpret the rest of the image in light of that.
Title text: Whenever I see a picture of the moon where the points go more than halfway around, I assume it's being eclipsed by one of those Independence Day ships and interpret the rest of the image in light of that.

Explanation

Ambox notice.png This explanation may be incomplete or incorrect: Table needs pictures. Title text needs explaining. Needs overall more detail.

The phases of the moon are created by sunlight reflecting off the moon's surface. This means that the bright side of the moon always needs to be facing towards the sun. However, the moon often appears in works of art in ways that are very dramatic, but violate this rule. This comic lists some of the some common mistakes. In some cases, a depiction may be unrealistic in multiple ways - for example, the Flag of Tunisia has both unrealistic horns and a star visible between the horns, while the Charles VI tarot shows a moon with over-long horns pointing towards the horizon.

Explanation of individual items in the list
Image Explanation Example
Full moon Normal -
Gibbous moon Normal -
Crescent moon with points away from horizon Normal -
Crescent moon with points towards horizon This can only happen when the sun is above the horizon. This isn't necessarily only during a solar eclipse, but since a crescent moon means that the Sun and Moon are relatively close in the sky, it's hard to see at other times. Van Gogh, Landscape with Couple Walking and Crescent Moon
Crescent-like moon where the black area doesn't touch the poles The moon is a nearly-perfect sphere, so when it's lit from one side, the dark side will always cover precisely 50% of its surface, and the dark area should begin and end on the moon's axis. If the moon looks like this, the shadows are in the wrong place. This is only possible during a partial solar eclipse, the start of an annular eclipse, or if the Earth is casting an extra shadow on the moon, a lunar eclipse. Randall labels the lunar eclipse "dubious", since the shadow during would be much fuzzier than shown here. Van Gogh, Starry Night
Crescent-like moon where the horns extend well past the poles Again, the shadow should just touch the poles. This situation is even harder to create than the previous one - the Earth's shadow is too big to cover the moon but leave an edge like this - a huge Independence Day spaceship (as per the Title text) might be the right size. It does however resemble a partial annular eclipse if you imagine that the black area is the moon covering up the white sun. Alcoholic Blues
Crescent moon blocking stars Normal -
Crescent moon with stars between horns As the moon is a huge ball, it should block the stars behind it. Many people seem to forget this[1][2]. If stars are visible, there are either one or more holes, or a light-source on the moon. As the Star and Crescent, the image is sometimes considered a symbol of Islam, although it's relatively recent and there's no traditional basis for putting the star between the horns - as originally used on the Flag of Turkey, the star appears in a realistic position. Edwin Blashfield, Spring Scattering Stars, the Dreamworks logo

Transcript

[Caption above the panel:]
Interpreting the shape of the moon in art
[The left part of the panel shows a two column chart is shown with labels above the columns. The left side shows the moons shape as white on a black square. These types of moons could be seen in certain art pieces. The right side saying whether this is normal or not as indicated with a green check mark or a red cross. Right of the second column there are explanations of why the specific type of moon is marked as it is and what it could be called or how it could be possible even with the red X. The upper three moons have one common explanation as indicated with a bracket that covers all three with the text on the middle part of the bracket. Similarly moon five and six also have a bracket and only one explanation.]
Shape Normal?
[Shape #1-3 shows a white circle (full moon), a more than half full moon (Gibbon) and a thin seal at the bottom right of the square.]
"Full" or "Quater" or "Harvest" or "Wax Gibbon" or whatever
[Shape #4 same as #3 but with the seal in the upper part of the square.]
X Only possible during a solar eclipse
[Shape #5-6 shows a full moon with a circular section taken out of the right side and a seal that goes almost all the way around the circumference of the moon with almost a full circle taken out of the top left part of the moon.]
X
X Only possible during a lunar eclipse (#1 only, dubious) or a solar eclipse (bright part is the Sun)
[Shape #7 same as #3 but with the seal a little smaller and more to the top and less to the left. Around the moon there are several starts represented with 29 small white dots. In the center of the black square there is a black circle, coinciding with the outer rim of the seal. Within this circle (the dark side of the moon) there are no stars!]
Look OK
[Shape #8 same as #7 but apart from the 29 small white dots from before there are now also 6 more dots inside the dark circle with no stars in #7.]
X There's either a hole in the Moon or a nuclear war on its surface.


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