# Questions tagged [moon]

A smaller body orbiting a larger, primary body, where the primary body is not a star.

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### Would the Moon move away if the Earth were frozen with no liquid tide?

The moon is moving further from the Earth. To the extent that after 600 million years we will no longer enjoy full solar eclipses as it will be too far away to completely block the sun. The reason the ...
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### What's the proper way to calculate neap low tide and high tide tide-raising forces?

My coursemates (and maybe, through them, my professor) insist that to calculate the neap low-tide tide-raising forces, I should take $F=\frac{GMa}{d^3}$ for a point on the earth $90°$ from the nearest ...
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### Magnetic compass working on the Moon and the Mars planet

Mars planet Moon Magnetic compass Theoretically and practically, will a magnetic compass work on the Moon and the Mars planet?
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### How long is a second on the moon?

The Office of Science and Technology Policy, part of the government of the United States of America, issued this statement outlining the need for a Lunar Standard Time (LST) standard. They state: For ...
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### I am trying to study moon position so that I can predict which direction which angle should I view from my small balcony to view moon

I have a small window through which I can view the moon only at some times for few minutes,I am keen to understand and study moon positioning to predict when shall be the next day I shall view moon ...
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### Finding the Cartesian position of the lunar ascending node

What I'm trying to derive The Cartesian position of the lunar ascending node relative to the true equator and equinox of date reference frame. My issue is I'm getting a bit tripped up with reference ...
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### Is it possible, by monitoring the brightness of stars, to find a “copy of the Earth + Moon” near them?

More than a dozen Earth-like planets have been discovered around nearby stars based on observations of changes in the brightness of their sun as they pass across its disk (transit events). If an Earth-...
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### How can tides even of miniscule magnitude occur in inland lakes?

Ocean water is flexible enough to allow water from each side of low tide to flow to the sides of high tide. So for a high tide, there must be a low tide somewhere else from where water is drawn out. ...
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### What happened to Newton 3rd law if our Moon is moving away at 1.5" yearly? [closed]

Our Moon is going away and I read that it is the culprit is our ocean, but then what happens to Newton 3rd law there should be an equal and opposite forces too so where's that? Is it absorbed by the ...
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### Why doesn't the Moon disrupt the orbits of geostationary satellites?

If a passing star can jostle comets in the Oort Cloud, why doesn't the Moon disrupt the orbits of high-flying satellites? Or does it? Maybe the satellites need periodic course corrections?
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### If the tidal bulge on the earth speeds the moon up, how does the moon move to a higher orbit?

I understand that the moon causes a tidal bulge on Earth, and this tidal bulge moves slightly ahead of the moon due to Earth's rotation. When reading about why the moon is moving away from the Earth, ...
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### How does a laser from Earth manage to hit the Moon with precision?

A question I've been asked is how a laser, fired from earth, would hit the moon without "leading it" (or hit it with precision). When firing a laser at the moon, it takes about 3 seconds to ...
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### If you are on the moon, would you be able to hear your hands clapping if you're not wearing your spacesuits?

As I understand it, sound needs a medium to travel and more often than not, the medium is the atmosphere, however sound can also travel through solid objects. And even we can hear our own voice ...
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### How much radiation on the surface of the moon during a Coronal Mass Ejection (CME)?

I'm writing a book set on the moon. A Coronal Mass Ejection (CME) as large as the Carrington Event hits it. Three astronauts are caught out during an EVA. They will cover their rover in regolith to ...
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### Do the line of Apsides and Line of Nodes of the Lunar orbit ever coincide (or change their relative position and does this explain Annular eclipses?

In the context of solar eclipses, my understanding is that an annular eclipse occurs when specific conditions are met, involving the relative positions of the Earth, the Moon, and the Sun. To be more ...
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### What does the sky look like from the moon?

From pictures taken on the moon, it appears that there are no stars visible in the sky, but I do not know if this is an effect due to cameras. What is the actual appearance of the sky on the moon? ...
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### Will the moon ever proceed to lose its orbit and hit the earth?

Assume that the moon it orbiting the earth in a circular trajectory. It will experience an acceleration directed towards the centre of the earth given by $\frac{GM}{R^2}$ where $G$ is the universal ...
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### Why does the Moon - which is grey - appear white to us even at daytime?

The color of the Moon as viewed more closely, is grey. But when we see it in the sky it appears white to us. Why? Although this question has some answers here: Why is the surface of the Moon white? (...
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### Why does water ice on the Moon not sublime?

I heard that water in form of ice was found on the Moon. Why would the ice not sublime (evaporate) due to low atmospheric pressure?
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### Has anyone experimented with simulating moon lighting?

Has anyone (in general) experimented with simulating moon lighting? It means the following. A gray ball is illuminated with light with a brightness equal to that of the sun. And at the corresponding ...
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### If the Moon suddenly got heavier/lighter, would it crash into/fly away from the Earth, or would it stabilize at a different orbit?

If the Moon became suddenly gained 20% of its mass, would it come crashing down to the Earth, or would it just stabilize at a lower orbit? Similarly, if it suddenly lost 20% of its mass, would it fly ...
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### When the new moon will become visible - after how many hours of conjunction

The moon will be totally invisible during Conjunction of moon, sun and earth. After how many hours of conjunction, moon will be visible from earth.
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### On the tidal heating of a moon. What is the second Love number?

Years ago it was asked here how to calculate the tidal heating of a moon orbiting another body with a simple equation. The answer is very detailed. They explain the equation, its shortcomings, the ...
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### What would be the period of a Foucault pendulum placed at the pole of the Moon?

How long does it take the Moon to rotate about itself once? There are two answers to this, the sidereal period and the synodic period. Sidereal period would be the quick answer to the question here, ...
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### Which parts of the electromagnetic spectrum cannot be used for remote sensing of the Earth system and why? Is that different on the moon? Why?

Which parts of the electromagnetic spectrum cannot be used for remote sensing of the Earth system and why? Is that different on the moon and if yes, why?
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### How to determine whether an atomic clock had "ticked at the Moon's natural pace"? (Nature 614, 13-14 (2023))

The recent news article "What time is it on the Moon? Researchers plan to build a lunar clock", Nature 614, 13-14 (2023) claims that "Clocks on Earth and the Moon naturally tick at ...
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### How exactly does the Moon stabilizes Earth axial tilt?

There are many references regarding the Moon stabilizing the tilt of the Earth's rotational axis. I'd like to see some support for that claim, more than non-sequitur handwaving "Moon causes tides,...
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### The radius of Earth is 4 times the radius of the moon. Estimate the acceleration due to gravity on the surface of the moon [closed]

I have derived an expression here which just needs the ratio of the densities of the Earth and its moon. My question is how do I go about finding this ratio or is there another way to approach this ...
1 vote
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### High school thesis project about Jupiter's moon Europa [closed]

So basically, I have to write a thesis paper because I'm in the last year of high school. It is an independent research project and the culminating work of my studies in school, so it represents my ...
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### Centre of Gravity of Earth-Moon Elevator [closed]

Suppose you have a cylindrical elevator that resembles a rod of mass $m$, cross-sectional area $A$ and uniform density $\rho$, with a length $L$ spanning the distance between the Earth and the Moon. ...
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### Are moons always smaller than the planets they orbit?

I'm not a physicist, asking for knowledge. Is there any moon orbiting a planet, but bigger than that planet? If not, is it mathematically possible for a bigger object to orbit around a smaller object ...
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### How much does the moon change in diameter as the gravity of the planets and sun act on it?

What is the maximum distortion of the moon? Is it measured in centimetres or metres or kilometres?
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### Would Aeroplanes or Helicopters work on our Moon?

Would Aeroplanes or Helicopters work on our Moon? In general , I think , in Aeroplane Case: (1) Air is required for Aeroplanes to float : Would Moon have enough air? (2) High speed is required for ...
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### Why is the time difference of equal tide states not 50 minute if one lunar day is 24 hour and 50 minutes?

I do understand that tidal forces are caused by de difference of gravitational force between both opposite points of the earth where a bulge is formed. I do understand that a lunar day is ruffle 24 ...
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### What is the rate of change of the Moon's eccentricity?

So I know the Moon's current average eccentricity is ϵ≈0.039±0.006, but was this always the case? Was it ever increasing or decreasing, and if so is it known what the current rate of change is for it? ...
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### If the Earth and the Moon were smaller, would moon tides be more or less intense?

If the Earth and Moon were smaller (and everything on them too, but keeping the same average density and the same "relative" distances, I mean... the same proportions!), would the tides ...
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### Weightlessness in Artificial satelite and moon

Why don't astronauts feel weightlessness in moon while they do in artificial satelite orbiting the earth?
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### Why is the Moon's gravity so high compared to its mass?

According to Wikipedia, the Moon's mass is about 1.23% of Earth's, but its gravity is 0.1654g or 16.5%. If gravity is proportional to mass, why isn't the Moon's gravity 1.23% of Earth's? EDIT: ...
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### White full moon reflected orange-red light off of Atlantic Ocean surface. Why is this?

I was flying over the Atlantic at night in near complete darkness. There was a white, bright full moon. It’s moonglade (the light reflected off the waters surface) was a orange-red color and not white....
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### How does the moon affect the position of zero gravity in the Earth?

I am interested in the position of the point of zero gravity within the Earth as a function of the gravity of the moon. Take the example of the moonless Earth. The position of zero gravity would be ...
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### Do solar flares move the dust on the surface of the Moon?

The TV show For All Mankind has a reputation for scientific accuracy, so I think it's fair game to ask if it lives up to this reputation. In this video clip, we see the dust on the surface of the Moon ...
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### NASA's explanation on tidal acceleration

I've found an animation in NASA's website, illustrating tidal acceleration effect between the moon and earth. It's the forth animation from the top in this page: https://moon.nasa.gov/moon-in-motion/...
1 vote
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### Black body side of the Moon

A few closely related questions regrading the Moon thermodynamics: The Moon is clearly not a black body, as it reflects a great deal of radiation incident on it. Still, it does absorb some radiation ...
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### Why do moons not get pulled into the planet while they clear their neighborhood? [duplicate]

Today, my 6 year old and I were discussing dwarf planets and their characteristics. We were talking about how, to be a considered a planet, the planet needs to clear it's neighborhood (as explained in ...
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### Could a moon keep orbiting a planet forever?

Our Moon orbits the Earth further away each year due to the tidal forces but could there be a moon orbiting a planet where somehow keeps going further away by the tidal forces but its attracted again ...
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### What's the time window for total and narrow eclipses?

Because of the tidal effect angular momentum is transmitted from Earth rotation to the Moons orbit around Earth. This means that perfect eclipses only has occured during a certain time window. Can ...
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### Is the position of the central peak of a crater on Moon showing that an asteroid hit it while it was not still sinchronised with Earth?

Is the position of the central peak of a crater on Moon showing that an asteroid hit it while it was not sinchronised with Earth? If the peak is in very center of the crater and the crater shown on ...
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### Why is it so dark during a solar eclipse?

At a total solar eclipse the sun is barely covered, like right after sunset. So why is it much darker than right after sunset (which allows us to see the corona)?
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### Are there any plans for cosmic ray detectors as part of the new ARTEMIS program?

NASA's new Artemis program involves building several temporary waypoints around and on the moon. One of the side-bonuses for scientists is that this has opened a few new funding avenues for studying ...
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