Questions tagged [the-moon]
Questions regarding Earth's only natural satellite. For questions about the natural satellites of other planets, use the tag [natural-satellite].
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Is the Moon only 60x60 pixels?
In doing research on vision, I have learned that "20/20" vision corresponds to a visual acuity of being able to resolve details 1 arcminute in size, that most people have around 20/15 vision,...
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How does the Earth move in the sky as seen from the Moon?
I just want to be sure I am visualizing this correctly, because it seems odd. The Moon is tidally locked to the Earth but there are wobbles to its motion due to libration. So from a point on the ...
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Why is only one side of the Moon visible from Earth?
Why do we only ever see the same side of the moon?
If this is to do with gravity are there any variables which mean we might one day see more than we have before?
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Why does Io cast a hard shadow on Jupiter, but the Moon casts a soft shadow on Earth?
Io (source):
The Moon (source):
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Why is moon light not the same color as sunlight?
The light from the moon is light being reflected from the sun. The sun, in space, is white. But on Earth, when the light is filtered through an atmosphere, the light appears yellow. So then, why is ...
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Is it possible to achieve a stable "selenostationary" orbit around the Moon?
Is there a stable geostationary orbit around the Moon?
My feeling is, that the orbit would collide with Earth, because of the Moon's slow rotation.
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Is Earth's moon the only one where a total eclipse of the sun covers the entire sun?
Is Earth's moon the only one where a total eclipse of the sun covers the entire sun?
Are any other moons the same size as the sun as viewed from their planet like Earth's moon?
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Can the moon appear to be in any position in the sky?
It seems to me that the Moon has appeared in many locations - apparent locations - in the 'dome of the sky'. I know that the Sun follows an arc from east to west and that the arc is smaller in winter ...
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How do we distinguish old craters from new ones on the Moon?
The following image is the observation made by the Dual Frequency Synthetic Aperture Radar (DF-SAR) onboard the Chandrayaan-2 Orbiter:
Due to image size restriction, a lower resolution image is used ...
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Why does the Moon appear gray when passing between the Sun and the Earth?
Shouldn't the Moon appear as bright as a full Moon seen at midnight from Earth?
The photo was taken by DSCOVR at Lagrange point 1.
In the picture, The Moon appears dark gray. Of course the Earth ...
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Is it a coincidence that on the far side of the moon almost no seas are visible?
Sorry for the maybe too large pictures. They do make the surface structures of both sides of the moon visible though. Is it just a coincidence that on the side facing us is so much sea is visible?
It ...
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If you lived on the far side of the Moon, how could you infer the existence of Earth?
Suppose that you deposit an astronomer, armed with our current knowledge of orbital mechanics, on a dome on the far side of the Moon, so that the Earth is perpetually hidden from them.
(And, of ...
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Why doesn't the moon twinkle?
Stars twinkle because their light has to squeeze through several different layers of the Earth's atmosphere. So why doesn't the moon twinkle as well?
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Is oxygen really the most abundant element on the surface of the Moon?
I found this infographic that seems to say that oxygen is the most abundant element on the surface of the Moon. Is this really the case? If so, under what form is this oxygen?
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Is this photocomposition of Andromeda's galaxy and the Moon accurate?
I recently saw the below image circulating around twitter/Facebook/reddit. It is titled "Andromeda's actual size if it was brighter":
One of the comments provides a link to another ...
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The moon has just the right speed not to crash on the Earth or escape into space. What are the odds?
My understanding is that the moon was created a long time ago when Earth was hit by a big asteroid.
The debris then agglomerated into the Moon, which happens to be orbiting at the exact speed required ...
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If months are based on the moon, then why are the months longer in the Gregorian calendar than lunation?
What I have always thought / known is that:
Days are based on the period of rotation of the earth.
Months are based on the moon.
Year is the time taken by the earth to make one revolution around the ...
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Where do we have it from that the Moon is migrating away from Earth?
I know Neil Armstrong placed a mirror on the Moon and people shoot lasers there which get reflected, thus measuring the time the light needs they can conclude the current distance of the Moon. But the ...
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If the Moon were impacted by a suitably sized meteor, how long would it take to impact the Earth?
An answer to the question of How well would the Moon protect the Earth from a Meteor? mentions as a possibility that the Moon could get knocked into the Earth.
What is the smallest change to the ...
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Is it possible to completely see the edge of a half moon at night?
Some days ago, about 1 ~ 1.5 hours after the sunset I could see a very bright half moon, and the interesting part is, I think I could see the edge of the dark half of the moon, i.e. a whole circle, ...
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What (the heck) is a Super Worm Equinox Moon?
Google News feed shows me the following.
What does the term "Super Worm Equinox Moon" mean and has it ever been used before this 2019 clickbait instance?
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Is it a coincidence that both the Sun and the Moon look of same size from the Earth?
The Sun is huge, when compared to the Moon. Despite the huge difference in their size and distance from Earth, is it purely coincidental that they both look almost the same from Earth?
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Why is the Moon's orbit so complicated?
I like to think I have a good enough understanding of astrophysics but there's still one thing that I just can't explain.
Why does the Moon orbit the Earth the way it does?
Many other moons in the ...
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Can the Moon eclipse Venus?
The title basically says it all. As seen from the Earth, is it possible for the Moon to eclipse Venus (or any other planet) or are the orbits inclined such that this never happens?
If such an eclipse ...
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Can you see man-made lights on the dark side of the Earth from the surface of the moon with the naked eye?
This question is prompted from a comment on this answer:
Could a person on the surface of the moon see man-made lights on the dark side of the Earth with the naked eye? If not, how much magnification ...
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Why does the Moon stablize Earth's axis?
In an academic study titled 'The Moon and the Origin of Life on Earth' it is said that
'If the Moon did not exist, the orientation of the Earth’s axis would not be stable, and would be subject to ...
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Puzzling quotes from astronauts about earth size
I have no doubt that we have been to the moon. This question has nothing to do with a moon landing hoax. But, there are two quotes from two different astronauts regarding the size of the earth as ...
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What ground-based observational evidence is there that the Moon doesn't have an atmosphere?
The Moon doesn't have any significant atmosphere (surface pressure is $3\times10^{-15}$ bar). Can the absence of atmosphere on the Moon be determined with ground-based observations? When was it first ...
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Does the Earth have another moon?
I was just wondering what are the chances that there is a small object (say less than 1 km but more than few meters) that orbits the Earth but has remained undetected by us? Are we actually ...
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Is the moon moving further away from Earth and closer to the Sun? Why?
According to The NASA Moon Facts page:
The moon is actually moving away from earth at a rate of 1.5 inches per year.
Why is the moon moving further away from the Earth? Is this a result of the ...
user96
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Where in space would the Earth and Moon appear to be the same size?
If I'm directly in between the Earth and Moon, what distance from the Earth would I have to be so that the Earth and Moon have the same apparent size?
How big would the moon appear compared to it's ...
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Where is it possible to observe the Moon for 24 hours?
I wrote an astronomy olympiad yesterday and there was one task I couldn't figure out an answer to:
Estimate at what latitudes it is possible to observe the Moon for at least 24 hours. Under what ...
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Have we ever observed a large meteor hit the Moon?
Since the moon has no atmosphere, its surface has many more meteorite impacts than Earth's does.
Image source
Have we ever observed a meteor strike the surface of the Moon?
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Why doesn't the Moon, like the Sun, turn bright red when it's close to the horizon?
Why does the Moon, being close to the horizon, turn red only slightly, or not at all?
Aren't the causes that lead to the coloring of the Sun (atmospheric refraction) are also true for the Moon?
In ...
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Apparent Ring of Craters on the Moon
I saw this picture on the BBC news website.
There appears to be a ring of craters in the center of the picture, aligned in an approximate sub vertical orientation.
Am I just seeing things or does ...
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Why is the Moon receding from the Earth due to tides? Is this typical for other moons?
After reading the Q&A Is the moon moving further away from Earth and closer to the Sun? Why? about the tides transferring energy to the Moon and pushing it from Earth, I have a question:
How is ...
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Is there any point on earth where the moon stays below the horizon for an extended period of time?
When I was teaching a class why the earth has seasons today, I mentioned how the poles of the earth experience months of daylight and darkness. Then one of my students asked whether the moon ...
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What is the distance that the Moon travels during one orbit around the Earth?
Also, does it always take the same amount of time, or does it fractionally differ on each revolution?
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Moon's unusual gravity
We know that the Moon's gravity is about one-sixth that of Earth. Then I recently read that the mass of the Moon is about one-eightieth the mass of Earth. Since gravity depends on the mass of the 2 ...
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During an eclipse, how big is the shadow of the moon on the earth?
This picture was taken from the ISS during a solar eclipse.
You can see the shadow of the Moon on the surface of the Earth. But how big is this shadow? How many kilometers is its diameter?
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Can impact craters on the moon act like giant radio telescopes?
Could large craters on the moon be used as reflective lenses for radio signals?
Acting like a large radio telescope reflecting radio waves to a satellite positioned over the crater.
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Do other planets in our solar system experience eclipses or is this unique to Earth?
Here on Earth we get to experience lunar and solar eclipses. Is this pure coincidence that everything happens to line up?
Do other planets in the solar system experience this phenomenon or is this ...
user96
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Will Earth lose the Moon before the Sun goes into supernova?
I've read that the Moon is moving away from the Earth by 1-3cm per year.
Is this enough to make the Earth lose the Moon before the Sun goes supernova?
I'm asking because I would like to do the ...
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Does the Moon have any oxygen in its atmosphere?
Since the moon has gravity, it's almost impossible that there aren't some gasses trapped on the surface by the moon's gravity. Has any free-floating oxygen been found on the Moon? If so, in what ...
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What is this 877-year cycle in the orbits of Jupiter & Saturn, and this multimillion-year cycle in the lunar orbit?
The book The Theory That Would Not Die (by Sharon Bertsch McGrayne, 2011) states the following on page 28:
He [Pierre-Simon Laplace] used other methods between 1785 and 1788 to determine that Jupiter ...
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Why does the moon sometimes appear giant and a orange red color near the horizon?
I've read various ideas about why the moon looks larger on the horizon. The most reasonable one in my opinion is that it is due to how our brain calculates (perceives) distance, with objects high ...
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Is there any telescope on Earth that can see the lunar rovers on the Moon?
If I have the right numbers, it seems to me that even the Hubble telescope might barely be able to make out a carcass of a blue whale on the surface of the Moon, which puts objects as small as the ...
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How do we know the moon is smaller than Earth?
The moon is smaller than the Earth, but how do we know that (without the use of modern technology)? To be more specific, how can we show that the moon is smaller than the Earth (smaller diameter) with ...
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Does the moon have days?
As like Earth, does the moon have a day (24 hours). If it has, how many hours are in a moon day?.
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Why would the side of the moon that faces earth be as dark as the far side of the moon?
Somebody suggested that the side of the moon that always faces the earth is as dark as the far side of the moon, but is that really the case? Doesn’t earth-shine make the earth-facing side of the moon ...
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