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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24
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3answers
3k views

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, ...
4
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1answer
69 views

How does using Tidal energy affect the moon?

Reading another question Where do we have it from that the Moon is migrating away from Earth? I makes me ask what effect does harvesting tidal energy for electricity production have on the rate the ...
2
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2answers
130 views

How can the Earth and the Moon be in synchronous rotation if the Moon won't be in geostationary orbit?

It is said that the Moon moves away from Earth and that during the Sun's red giant or white dwarf phase the Moon will be about 40% farther than now and in a synchronous rotation ("hantle rotation&...
2
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0answers
36 views

Can tidal locking increase rotational kinetic energy? Where does the energy come from then? [closed]

I was thinking about the explanation for how the Moon gets tidally locked with the Earth. We are working in the non-rotating reference frame of the Earth, and assume it is inertial (to an approximate ...
1
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1answer
94 views

Sunrise and Moonrise time are same [duplicate]

I checked an app and saw that today, the sunrise and moonrise time are almost same. The sunset and moonset time are also same. Why does this happen? I have always known that moon rises at night and ...
-4
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2answers
111 views

Why is the Moon's volume so small compared to the Earth's?

The Moon has 27.3% of the Earth's radius/diameter but only 2% of the Earth's volume. I don't quite get it why the Moon's volume is that small despite having more than a quarter the 2-dimensional size ...
4
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2answers
56 views

Is there an advantage to the equatorial region of the far side of the moon for a radio telescope or would any crater on the far side work?

If nearly any crater on the far side of the moon will work, and not just equatorial craters, then we could pick craters near the possible future Artemis base at the South pole which would allow easier ...
26
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2answers
8k views

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, by this, measuring the time the light is needing, they can conclude the current distance of the ...
3
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2answers
3k views

What would be the practical consequences (on earth) if the Moon was not tidally locked?

I was thinking about the fact that all the largest Solar System moons are tidally locked to its primary and this question arose.
3
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1answer
51 views

How did DSCOVR capture the Moon's shadow on Earth during the August 21 2017 solar eclipse without the Moon itself also being visible?

In this gif you can clearly see the Moon's shadow moving from the West Coast of the U.S. towards the East Coast during the August 21 2017 eclipse. DSCOVR (the satellite that imaged this) is located at ...
5
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2answers
2k views

How to explain this trajectory of the moon taken from the same spot on Earth over 28 days?

Found this picture online, was wondering why the trajectory has taken such a beautiful shape ?
2
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1answer
267 views

How to calculate the moon phase angle?

I need to calculate the exact moon phase angle for each our of a day. I have my position in lat and long and a unix timestamp. At the end i would like to be able to caluculate the moon brightness with ...
4
votes
1answer
112 views

Isn't it absurdly unlikely that our Moon would constantly be “facing” us? [duplicate]

I never thought about this until recently, but our Moon is constantly rotating in such a way that it happens to perfectly be "looking at us" at all times. That sounds incredibly unlikely to ...
2
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1answer
2k views

When will the next summer solstice and a full moon coincide? What day?

What day will the summer solstice and full moon coincide? As far as I know the next time will be in 2016. I would like to know what day.
2
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1answer
40 views

What are the Kinematics / Dynamics behind the motion?

https://www.timeanddate.com/eclipse/in/@8133395?iso=20200621 The link I have attached is a predicted model for the eclipse in my area! I am very much confused about the movement of the moon analogous ...
7
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2answers
282 views

Computing orbit positions of Jovian Satellites / Moons using JPL data

I've been trying to build a model of the solar system in a game. Thus far I've succeeded in placing each of the planets in position using Keplerian elements and formulae from https://ssd.jpl.nasa.gov/...
22
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3answers
5k views

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 ...
2
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0answers
36 views

Keplerian Elements for the Moon and Earth around their Barycenter

So I'm looking to replicate the inner Solar System to a decent degree of accuracy. So far I've been utilizing the Keplerian Elements and Equations for the planets, as shown here. There is one issue ...
1
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0answers
86 views

Best response to shut down the fake Moon landing conspiracy [closed]

This Question was closed for various reasons. For people looking for the answer to similar question, please see this link. I believe this is a solid answer to my question. As the designated Space ...
4
votes
2answers
976 views

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 ...
3
votes
1answer
128 views

Historical lunar occultation of Venus seen from Sicily in the winter?

I am looking for dates in history, from 400 years ago or older, when there was an occultation of Venus by the Moon during Winter as seen from Sicily. Venus was rising, and according to the text that ...
5
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3answers
945 views

Why doesn't the moon always follow the same path? Or why aren't the moon's apoapsis and periapsis fixed?

I have seen many times that the moon doesn't follow the same path. Sometimes the moon gets very close to earth which is shown in the news. If the periapsis of the moon is soo close then why doesn't a ...
10
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2answers
2k views

Can a bullet be fired on the moon and sent it into orbit?

I know you need oxygen for the ignition, but presumably, if the bullet is impervious (or water-tight) and if there is a little air enclosed in the bullet case, wouldn't that be sufficient to fire it ? ...
53
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5answers
5k views
19
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1answer
1k views

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 ...
2
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1answer
2k views

Is there a simple, analytical formula for the lunar phase brightness curve?

Brightness of the lunar disk varies as a function of phase angle. This phenomenon is very well established, as is the increase in brightness at low phase angles. Is there a simple analytical formula ...
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0answers
32 views

Ladakh India where the moon (Ramadan moon) is sighted but not in rest of India [duplicate]

Today 22 May 2020 around 3 p.m Ladakh India sighted new moon(Ramadan moon) but not in rest of India.I read many articles acc. To them it is not visible today, then how it was seen from Ladakh... .
1
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2answers
71 views

First visibility of the moon

I am new here, and hope to state the question well. In Islam, it's known that the Lunar Month starts if the Moon is sighted after the sunset of the 29th day of that month. If someone claimed that ...
13
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8answers
5k views

Moon's orbit around the Sun

The Earth revolves around the Sun and the Moon revolves around the Earth. Out of curiosity I started thinking about the orbit of the Moon around the Sun and expected (assumed) it to be as follows: ...
4
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0answers
48 views

How will the Solar tides affect the Earth's rotation once it is tidally locked to the Moon?

It is my understanding that the tidal forces of the Moon acting on Earth cause it to slow down its rotation and, because angular momentum is conserved, the Moon's orbit subsequently expands. This ...
-3
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1answer
95 views

Where is the Moon?

I live in Western Australia and I have not seen the moon for almost a solid week. Last I saw it it was almost full, and the sky has been clearer than ever with all the stars bright and visible yet the ...
2
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2answers
282 views

Is it possible to explain the difference between synodic month and sidereal month by degrees?

Is it possible to explain the difference between synodic and sidereal month by degrees - in the following way? Just recently I learnt about these two types of months, and I want to see if I can ...
2
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1answer
99 views

How to calculate moon overhead and underfoot time?

For hunting purposes, some hunters follow the moon phases to hunt accordingly. To give some context, here's some links: Lunar cycle's effects on hunting: https://www.acurite.com/blog/weather-stations-...
0
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1answer
44 views

What symbol is used for the moon when doing calculations?

When doing calculations the mass and radius of the Earth can be represented by $M_{\oplus}$ and $R_{\oplus}$ respectively. The planets all have their own symbols which can easily be found online. ...
5
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4answers
3k views

Difference in time between sunset and moonrise on a full moon

So as a Sailor I have experienced some times where sunset and moonrise are very close together (this happens when it's full moon) which is particularly beautiful. I assumed that this was always the ...
3
votes
1answer
65 views

How accurate should sun\moon ephemeris be for calculating eclipses?

I am writing a program to simulate eclipses for about -2000 to 6000. My question is, how accurate does my ephemeris for the sun and moon have to be to get a decent accuracy for eclipses? I currently ...
2
votes
1answer
44 views

Determining moonset time from Nautical Almanac

I have recently learnt to determine moonrise and moonset times using the Nautical Almanac, as part of my maritime navigation course. I have a query regarding the determination of moonset times. I will ...
1
vote
1answer
90 views

Do Astronomers really never call Lagrangian points “libration points”?

In this answer to Who called the Lagrangian points as “Libration” points and and why was the terminology “Libration” used? I described my feeling that Lagrangian points were also sometimes called &...
5
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1answer
5k views

When did the Moon become tidally locked to Earth?

According to various theories the Moon was created around 4.5 billion years ago. About all of these theories suggest that it was rotating around its axis at that time though. Currently, Moon is at ...
2
votes
1answer
92 views

Temporary family member 2020-CD3

So, recently I came to know that this asteroid is orbiting Earth from past 3 years and still it is orbiting. It is kind of a mini Moon to the Earth know to have come from asteroid-belt. Is there ...
2
votes
1answer
63 views

Can lunar occultation of Venus occur during solar eclipse?

Moon can occult Venus. Venus can transit across the solar disc. Moon can elipse Sun. Can all three celestial events occur at the same time - Moon is at front of Sun (partial eclipse is fine) and Venus ...
4
votes
2answers
70 views

Where is the sun relative to my lunar rover?

I'm a robotics researcher writing orienteering code for a solar-powered lunar rover. I have two similar problems: Given the position of a robot on the moon in lunar latitude/longitude, where is the ...
1
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0answers
28 views

Lunar surface illumination

I am trying to determine the lunar surface near or far side daytime illumination levels in Lux or foot-candles but there seems to be no directly measured values available. I did find this information ...
-1
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1answer
76 views

Why the time that the moon orbits the earth is becoming shorter and shorter?

I read in past that the time that the moon orbits the earth is becoming shorter constantly? (0.3 seconds per 1000 years) and what is the simple astronomical explanation?
1
vote
1answer
91 views

Implementing the VSOP-2000 Ephemeris

For a project I'm doing, I need to implement the VSOP-2000 ephemeris for the Moon. However, unlike VSOP-87, there is little to no documentation online on how to use the data. For example, here is the ...
18
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3answers
3k views

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?
1
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2answers
94 views

Moon’s orbit shift

Has our moon’s orbit shifted since its formation? Has there been eclipses on the Earth since last ~4 billion years? In other words, was there a time when Moon's orbit was at an inclination to Earth's ...
1
vote
1answer
48 views

Simple question about the phases of the Moon

If on March 20 the Moon were located at the position of the sun, how can I determine the phase in September 22, June 22, and December 20? I drew the orbit and calculated by dividing sidereal days to ...
5
votes
1answer
132 views

Sun, Moon: Relative Distance from Crescent?

This is more a question about the history of astronomy. It recently occurred to me that you can estimate the ratio of earth-moon and earth-sun distance in the following way: We can look at the ...
1
vote
2answers
80 views

Right Ascension to Zodiac House

At the moment (01-04-2020 09:36) the Moon is situated in Gemini: "The Moon is currently in the constellation of Gemini. The current Right Ascension is 06h 37m 56s and the Declination is +23° 42' 09”."...

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