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Actually, it is rotating relative to your perspective. (The other answer relating to liberation occurs over a longer period of time). Here is a simulation from Sky Safari for later tonight (moonrise) and tomorrow (moonset) for my location. Note how the angle of the lit hemisphere rotates between the pictures: Moonrise: Moonset: It looks like this ...


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This effect is called libration - and it is an oscillating motion of orbiting bodies relative to each other (from Wikipedia) It is down to three factors: The Moon's orbit is not a circle, so it moves ahead and behind where it would be on a true circular orbit Where you stand on the Earth moves during the day relative to the Moon The Moon's orbit is ...


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+taupunkt basically answered this: the thin lunar crescent after New Moon is only visible for a short while after sunset. While the sun is up, the moon is invisible and it becomes visible when, after sunset, the sky turns dark enough. However, the moon will set typically 1-2 hours after sunset, and will become invisible some time before that due to ...


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Since human beings appear to have a biological sleep cycle close to an Earth day, I would strongly suspect that extraterrestrial human colonies would keep this rhythm. People living close to the poles of the Earth, where it is light all summer and dark all winter, don't stay awake for half a year and then sleep the other half. Similarly, it doesn't make ...


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Let's start answering your question in reverse. Ceres could not be "the missing Theia" (I know you don't say that; I'm addressing a side issue) because of its shape. If an object hit the Earth at an angle (as is currently thought), it would be pretty deformed, if it managed to stay together. If it hit the Earth head on . . . Well, it would almost certainly ...


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As we view it, the moon moves westward across the sky due to the rotation of the earth, while at the same time it's moving eastward in its orbit at about 1 lunar diameter in about 57 minutes, or about 1 lunar diameter per hour or 12-14 degrees per day. That's why the moon can be seen blocking out (or occulting) a bright star or planet as it slowly moves ...


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If you go far enough north or south, you will reach a latitude where the moon can be below the horizon for several days, just like the 'midnight sun'. It can also be above the horizon for several days for the same reason. At the north or south poles, the moon may be either continuously above or below the horizon for nearly 2 weeks at a time.


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Of course the apparent relative sizes of the sun and moon are coincidental. What other rational explanation is there? Maybe NASA built the moon that way on purpose. LOL oops ... "For reference, the Moon is currently at a distance of approximately 37.5 Earth radii." I wonder where that odd figure came from. This "37.5" radii figure is very inaccurate. ...


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You can imagine that if you hopped into a rocket and blasted off in a lateral direction, you would be able to view the moon from a different perspective and see more and more of the side illuminated by the sun. But the earth is only about 12,700 km across whereas the earth-moon distance averages about 385,000 km. That means that the angle you are viewing ...


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I really love this question. Were we to establish a colony on our moon, we would probably want a calendar/time system which actually corresponds to physical patterns and cycles on the moon, but also something which is easy to track and keep in sync with Earth, since the two civilizations would certainly be in close contact. In a way, we already do something ...


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I take it you're looking for something absolute to measure time with, such as revolutions around a planet or the planet around a star? If so, you could use a "year" to be the time it takes the planet to orbit the star, or the moon to orbit the planet. Those could also be used as separate, unrelated measures of time. A "day" could be construed as the time it ...


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No, the orbiting rocket was not visible to the naked eye. Orbiter plus lem were about 65 square meters in size, about 25 X 25 feet. At lunar distance they subtended about 0.000001 square degrees, and be at most 5 to 10 times as bright as the lunar surface; albedo 0.5 to 1 vs 0.1. A speck 1/1000th of a degree on a side, and a little brighter than the moon is ...



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