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Questions tagged [the-moon]

Questions regarding Earth's only natural satellite.

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Is the moon “perfectly” tidally locked and, if not, how long would it take us to observe it's rotation?

I have a general understanding of how and why a body in space can be tidally locked to it's planet or sun and I'm aware that our moon is in such a state. My question is, if our moon once had a ...
3
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1answer
385 views

How do we know that a natural satellite cannot be a hollow object?

In their 1966 book, Intelligent Life in the Universe, Carl Sagan and Iosif Shklovsky state that "a natural satellite cannot be a hollow object." How do we know this is absolutely true?
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1answer
295 views

How do we get the angular size of a crater without lens?

Suppose I want to calculate the diameter of the crater. I apply the small angle formula $$diameter=\frac{\theta_{diameter}}{206265''}\times D$$ where $\theta_{diameter}$ is the angular size of the ...
3
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2answers
293 views

Length of a tidal day or by how much is the Moon late each day?

A tidal day is the MEAN time between successive meridian transits of the Moon. (This is sometimes called called a lunar day, a term that should be deprecated for use in this sense, because it is also ...
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0answers
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How close must a full moon be to become a supermoon?

According to this answer there is a scale of super moons depending on how close the full moon(henceforth anti-sol) is to perigee. So how close to anti-sol does the moon's perigee need to be to be ...
3
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1answer
147 views

What made the recent supermoon so super?

I understand that a "regular supermoon" is a full moon when the moon is at perigee (closest to earth in its orbit). They seem to happen often, here's a post from one last year. But I've seen news ...
3
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1answer
294 views

How can the next supermoon be analytically predicted?

The lunar motion can be predicted with basic celestial mechanics, but the perigee and apogee are not always the same, basically because the attraction of the Sun makes some oscilations in the semi-...
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2answers
179 views

What would be the difference in distance between earth and moon on supermoon night (14 November 2016)

As we all know the usual distance between earth and moon is 384,400 km. But i was thinking how much closer it will be on 14 November 2016, as it will be a supermoon, the brightest and biggest moon in ...
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3answers
177 views

Why and how the Moon experiences only slight tidal forces [closed]

I understood the literal meaning of the red-underlined sentences, but frankly speaking, I don't know the processes. I mean I want to know how Earth's rotation makes a cycle of two high and two low ...
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1answer
298 views

Is it possible that Fly a Boeing 777 plane on Moon? [closed]

i always wondered that Is it possible that Fly a Boeing 777 Air Craft on Moon? if cannot how this moon lander's (Apollo) landing in Moon taking off from the moon?
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1answer
560 views

Recurrence of Moon at Virgo's “feet”

A friend of mine saw a video that claimed the moon appears to be at the feet of the constellation Virgo about once every 17 years with its next occurrence being in September 2017. Is there any ...
9
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1answer
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Will the Earth ever be tidally locked to the Moon?

From my basic understating, Momentum is being transfered from the Earth's rotation to the Moon's orbit by tidal friction. The Earth's rotation slows down and the Moon receedes from the Earth as it ...
2
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1answer
189 views

How to know when the moon is visible on a particular night?

I am looking for beginners information on how I can know when the Moon is going to be visible on a particular night ? Google-fu says to look for moonrise information about my city from websites such ...
4
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1answer
239 views

Why does the Moon's terminator look “wrong” in this image?

There is a picture of the moon in National Public Radio's on-line article Get Ready For Halloween By Watching The Moon's 'Occultation' Tonight. It looks wrong to me - specifically, the brightness ...
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0answers
58 views

The drift of the Moon's equatorial rotation velocity

Are there any citation or documentation showing the measured degradation of the Moon's equatorial rotation velocity (thus affecting its moon's axial rotation)? I am looking for the drift of the Moon'...
4
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2answers
263 views

From our world's perspective, does the full moon look larger in one city than it does in another?

When I was a very little girl, my dad talked about the HUGE full moon he saw while in the navy. He made the comment during a full moon we were having in Western NYS. He said, this (harvest) moon is ...
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2answers
2k views

When the moon eclipses the sun what direction is darkened first: left or right?

I saw the question and answer for the explanation of the direction of the moon's eclipse from left to right, but what about the direction of the moon as it passes over or between Earth and the sun? ...
8
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2answers
3k views

Why haven't I seen the Moon?

It has been some time since I've seen the Moon. What are the conditions that might affect whether or not the Moon is visible within a 24-hour period? Please take into consideration any notable ...
9
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2answers
400 views

How easy would be to see the Moon from Mars?

This question arises from "What planet is better than earth to infer solar system configuration?", where one of the answers pointed that it's easier to discover the Moon from Mars than discovering the ...
6
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2answers
633 views

Can Earth host another natural satellite than the Moon?

Are there orbits with long-term stability (astronomical time scales) around Earth? Low altitude orbits will decay due to friction with Earth's atmosphere. Inside Earth's Roche limit, a Moon could not ...
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1answer
351 views

The Hollow Moon Story [closed]

I've heard on various programs (yes TV) with "supposed" experts in various fields that there is evidence which would suggest that the moon could be hollow. The experts ranged from scientists, sound/...
16
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3answers
7k views

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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1answer
49 views

Observations of a perigee coincident with a full Moon

Hopefully this will be a quick and easy question, with a quick and easy answer, but why is it that we observe a perigee Moon coincident with a full Moon approximately every 13 months? Is this related ...
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2answers
173 views

Can radio telescopes such as arecibo image the subsurface of asteroids or planets?

This was done with the moon: Radio Dishes Peer Beneath Moon's Surface
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1answer
333 views

Why is the Lunar Node in a daily motion?

I've read a lot about the Lunar Nodes online (on Wikipedia, astro.com and a bunch of other websites), but there is one thing I cannot figure out and the sources don't seem to clearly explain: why are ...
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1answer
116 views

How many rovers now on Moon? [closed]

The Apollo missions took moving rovers to the Moon. How many moving rovers are presently on the Moon?
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3answers
317 views

Is there any residual oscillation left from the Moon rotation?

The Moon is tidally locked to Earth - a long time ago it was spinning, but after a time, the spin stopped - two factors stabilizing it: unequal mass distribution creating an equilibrium position where ...
2
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2answers
2k views

Why are tides biggest during the equinoxes?

I've read that during the equinoxes, tides are at their maximum. Shouldn't this only apply to latitudes near the equator? I mean, when the solar declination is near to 0º and we have a full or new ...
29
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4answers
3k views

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 ...
2
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2answers
344 views

Is this a real picture of the moon?

I found this picture and I am really wondering if it is possible for the moon to get as close to the earth as this picture shows? ( Super moon above Rio De Janeiro)
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2answers
352 views

How often is a blue moon?

A blue moon is two full moons in the same month. How many times will a blue moon occur in the average lifetime of say 70 years?
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1answer
67 views

Has anyone filmed a total lunar eclipse from the Moon's perspective?

With all of the footage we have of total lunar eclipses, has NASA, ESA, or any other space program ever taken a photo or video of it from the Moon itself?
2
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2answers
841 views

lunar calendar accuracy for predicting new moons

I wonder, how accurate the lunar calendar is? Can we predict the new moons precisely for tens of years in future? If we know all factors that affects the movement of the moon, then why it is not ...
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2answers
456 views

Has NASA confirmed earth now has a second moon orbiting the planet?

Several sites claim NASA has confirmed a second moon orbiting earth. This is the Asteroid 2016 HO3. One source states The newfound quasi-satellite/moon-2016 HO3, is likely larger than 120 feet (40 m) ...
6
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6answers
367 views

What color is earthshine?

What color is earthshine (e.g the average color of earth that shines on the moon)? I am making a solar system exploration game, and would like to know this for the lighting of my moon level at night, ...
0
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2answers
197 views

Two moons and one Earth? [closed]

Can any one explain to me What will happen to Earth if its has two moons? Same Distance & two sides of earth (North & south)? Will it be good for humans or bad?
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1answer
49 views

What is the name of the cycle whereby the lunar azimuth and altitude recur on a given day?

Like the Metonic cycle, except for position in the sky, not phase. Original question: If I look up at the moon tonight, how long before it is in the same apparent position, and same phase, again? I ...
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3answers
407 views

What would Earth be like without the Moon?

If somehow our moon was destroyed (for example by an asteroid) what would happen to Earth? Would the Earth be affected by the absence of the moon? Would humans be able to live normal lives without ...
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2answers
85 views

Is it possible for the year to have 11 full moons (i.e. the opposite of a blue moon)

A blue moon is so called for when we have 13 full moons in a year. https://en.wikipedia.org/wiki/Blue_moon Is it possible to have 11 fun moons in a year? (Maybe if we included calendar changes, for ...
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1answer
62 views

Appearance of the Cresent [duplicate]

Does the latitude of your position on earth change the appearance of the cresent like it changes the position of other objects visible in the sky? Does it rotate it?
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1answer
327 views

Why aren't people going to The Moon any more? [duplicate]

In 1969 America landed on the moon, and at that time our technology was not as good as it is now. So my question is, we have much more advanced technology than in 1969, so why are we not utilising ...
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1answer
69 views

LLR & Orbital Motion

As I understand it, light that is emitted from a source is not imparted with the motion of the source and so always follows a "straight line". If this is correct, I am having a difficult time ...
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2answers
977 views

Is it possible for the Sun and the Moon to crash into each other? [closed]

Is it possible for the Sun and the Moon to crash into each other? If yes, under what conditions? If no, why?
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1answer
1k views

What is the first recorded reference to the Moon being a satellite of the Earth?

I saw a list recently of the moons of the various planets and the discoverer(s) and date of discovery. Earth's Moon was listed as Unknown. I know you don't 'discover' a huge disc in the sky. But ...
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1answer
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Can you see city lights on the Moon from Earth?

This is the opposite of another question. That question is about whether you could see cities on Earth if you were standing on the Moon. Let's there are cities on the Moon and you're standing on the ...
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1answer
105 views

The relation between the light of full moon and the distance between the sun and the earth

If we want the full moon to be 2 times more bright,how we should change the distance between the sun and the earth? Thanks for your help.
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1answer
95 views

What makes the Moon and Venus shine?

Is there some substance on Venus or some kind of material, because neither bodies have any source of light.
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2answers
147 views

Far side of the moon question

Do all / most / any other moons orbiting a planet synchronize their rotation so as to become tidally locked with it, or is the earth a special case?
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1answer
157 views

Longitude of the Ecliptic

I originally went to math.stackexchange.com and they suggested I try here as well. I'm trying to figure out how to calculate times of moonrise and moonset for a given position on the earth on a ...
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2answers
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Solar / lunar positions in ECEF using SOFA C libraries

I'd like to calculate the positions of the sun and moon in the ECEF coordinate system using the SOFA (http://www.iausofa.org/current_C.html) libraries given a Julian day input. So far, I've got this ...