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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15
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3answers
2k views

Was lunar libration first observed or first predicted? In either case, who was the responsible party?

How old is the idea of the far side of the Moon? got me thinking that as soon as we see the moon librate we have to come to terms with there being even more of it we can't see. The Moon's libration is ...
3
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1answer
229 views

How old is the idea of the far side of the Moon?

The far side of the Moon is the side which always faces away from the Earth, due to tidal locking. Due to libration, about 18% of this far side can be seen at one point or another through telescopes. ...
3
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0answers
28 views

Projecting shadows, or even a movie, on the moon [migrated]

Would there be a way to project shadows, or even a short movie on the moon, i.e. using the moon as a cinema screen and the sun as a projector? To be more precise, if a cubesat was launched towards the ...
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0answers
52 views

Which edge of the Moon was deeper submerged into the Earth's shadow?

I was trying to solve this little task: An Australian astronomer at the latitude of Melbourne (-38 °) observed a series of unusual events. First, he watched the setting of the sun and the rising of ...
20
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4answers
4k views

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 ...
11
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3answers
3k views

Can you see the shadow of a spaceship on the Moon while looking towards the Earth?

It's a classic movie cliche. We see the surface of the Moon with the Earth in the distance and a dark shadow of an invading alien spaceship slowly covering the landscape. We see this in the opening ...
3
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3answers
177 views

How to calculate the nodal precession range of the Moon with respect to the celestial equator?

In the span of 18.6 years there is nodal precession of the Moon with respect to the ecliptic of 360 deg. But if we consider this precession with respect to the equator, we will find (unless I'm hugely ...
2
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2answers
90 views

do meteroid impacts occur evenly across the entire moon surface?

Since the moon is tidally locked and has the same face showing to the earth, I would expect that the earth's shadow represents an area on the moon that would be spared some meteoroid impacts. Does the ...
2
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0answers
39 views

Up to what distance from the Moon does the Moon's gravity hold its exosphere before it is being cast away by solar wind?

Up to how far from the Moon is the Moon's exosphere gravitationally bound to it? For the Earth's exosphere it is 120,000 mi (190,000 km) or half the Moon's distance from the Earth, beyond that the ...
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0answers
26 views

Where can I find rise, set & phase data for the MEAN moon?

I am trying to design a javascript time-and-tide-clock for a website. The clock starts when the page is loaded with the initial positions of the time hands pointing to the current time of day. The ...
1
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1answer
61 views

Why Does Moon Evection formula use the mean position instead of the true position?

Reading Wikipedia on the Moon Evection, and was somewhat surprised to find there that the formulas to express the evection are using the Moon's Mean position (mean anomaly) instead of its True ...
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0answers
43 views

Are new Moons (and full Moons) more probable to happen around certain ecliptic longitudes?

The average lunar synodic month is 29.53059 days. Because of these variations in angular rate, the actual time between lunations may vary from about 29.18 to about 29.93 days. The average duration in ...
1
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6answers
164 views

Am I looking at the moon upside down here in the US?

This may be a very basic question, but I just learned that the moon orbits around the earth counterclockwise. I always thought the earth and the moon shared the rotation and orbit direction. Since the ...
3
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0answers
114 views

Why does our Moon not have rings?

While our Moon is full of craters, one could consider that these events might have been enough to release amounts of fragmented mass into the Moon's orbit sufficient to establish some sort of ring. ...
0
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1answer
125 views

Structures on the Far Side of the Moon?

I downloaded an image of the far side of the moon using Google Earth. It is an area to the North West of the Mare Moscoviense (lat 27.3$^{\circ}$ lon 147.9$^{\circ}$) What are the dot-like structures ...
2
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2answers
86 views

Why does the difference between terrestrial times and universal time, $\Delta T$, have such a strange behaviour?

I was reading about ancient astronomy, and one of the main phenomena described is eclipses. Now, I read this 2016 paper by Stephenson, Morrison and Hohenkerk, in which they determine the values of the ...
3
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2answers
108 views

When can Moon occult Venus?

I'm trying to solve this task: At what age of the Moon (in days after the new moon) is it possible for the Moon to occult Venus? How I was solving it: Angular velocity of the Moon is 13.2 degrees ...
2
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2answers
143 views

What percentage of the time can we see the moon during the day?

From sun rise to sun set what percentage of the time is the moon visible? I saw one thing at the top of google saying an average of 6 hours a day but that seems like a weird way to answer it. Would ...
4
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0answers
205 views

Trying to find the source of these three orbital elements

I'm working through section 65 “Calculating the Moon's position” in Practical Astronomy with your Calculator or Spreadsheet (fourth edition) by Duffett-Smith and Zwart. They begin the calculations ...
16
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3answers
5k views

Can large scientific telescopes observe the Moon without being damaged?

When I look at the full Moon through my 10cm telescope, it is so bright that it hurts. Can large scientific telescopes observe the moon at all? Does that require special protection equipment? Or ...
16
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1answer
3k views

How can an area be on the day side 90% of the time?

In the magazine "Ciel & Espace", it is stated that crater ridge next to Shackleton crater is an interesting landing site for future missions because it is lit up 90% of the time. I get ...
1
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1answer
39 views

Is it a partial lunar eclipse or a partial phase of a full lunar eclipse?

I'm trying to solve this task: What is shown in the photo: a partial shadow eclipse of the Moon or a partial phase of a total eclipse of the Moon? I can't really understand it. Could somebody help ...
1
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2answers
206 views

What was the day of the week for the total lunar eclipse (saros 61) that occurred on April 14, 32 AD?

I am interested to know if there is convincing "astronomical" evidence/data to pin down the exact day of the week for the total lunar eclipse of April 14, 32 CE. I am hoping that perhaps ...
2
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1answer
53 views

When could solar eclipse happen in a way that Sun's disk is diminishing from below?

I'm trying to solve this task: During a solar eclipse, an observer noticed that the diminishment of the Sun's disk began directly from below. Where and when could this be? Concerning "where&...
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3answers
175 views

Why doesn't the Moon fall out of orbit?

If you need to boost ISS to stay in orbit why moon doesn't fall down to earth and KABOOM?
3
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1answer
596 views

Could there be an eclipse tomorrow if the Pleiades is covered by the Moon tonight?

I'm trying to solve this task: Suppose today there is a covering of the Pleiades star cluster by the Moon. Could there be an eclipse of the sun tomorrow? The moon? I think the answer to both is no, ...
2
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1answer
159 views

What would happen if the Sun, Moon and Earth were isolated?

I am curious to know what would happen to Earth and life on Earth if all other heavenly bodies outside of our Sun, Moon and our planet Earth ceased to exist in some non-destructive way? (this includes ...
4
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2answers
389 views

How to resolve the Moon's observed angular velocity with that given by Kepler's Third Law

According to the sidereal period of the Moon's orbit around the Earth of 27.32166 earth days of 86400 seconds we get an angular velocity of $\frac{2\pi}{27.32166×86400} = 2.6617×10^{-6}$. (NASA's ...
4
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1answer
97 views

Would people on opposite sides of the earth see different details of the moon, if so are there actual photos demonstrating this?

I am aware of phases and the fact that opposite sides will see the moon flipped relative to the other but what I’m asking specifically is would the almost 8000 mile difference between the two ...
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0answers
31 views

What is the size of the universe? [duplicate]

Will as a result of the continuation of technological progress in the twenty-first century more perfect telescopes or other astronomical instruments that will allow to know what is on the surface of ...
1
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1answer
66 views

What are the aspects does the moon differs between cities located on the same latitude?

What are the aspects does the moon (astronomical position and other astronomical aspects) differs between cities located in the same latitude? - For example: Seattle, Munich, Vienna, and Ulaanbaator ...
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3answers
321 views

How to find the the diameter of the moon during a total solar eclipse?

I am not able to find the diameter of the moon. I have the following question in my physics textbook: During a total solar eclipse the moon almost entirely covers the sphere of the sun. Write the ...
5
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2answers
165 views

Moons with synchronous rotation in our solar system

Are all moons in our solar system rotating synchronously around their planet? If not, what are the criteria that some do and some don't? Many thanks for any insights!
3
votes
1answer
149 views

Moon's rotation and revolution

Since the moon's period of rotation around its own axis, and that of its revolution around earth is (almost) same, we always see only one side of moon. This is what was, & is taught in schools. ...
1
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1answer
38 views

What is Lawrence Krause's theory of total energies?

Does Lawrence Krauss theory say that the total energy in the universe is equal to zero or that the energy in the entire universe remains constant and the mass in the entire universe also remains ...
0
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2answers
107 views

Conversion of Moon's Celestial Position (RA and dec) to Horizontal Coordinates [closed]

I'm currently attempting to calculate the equatorial sky position of the Moon for any given Geostatic position (longitude / latitude) for any given datetime. I have tested my altitude and azimuth ...
37
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3answers
6k views

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 ...
-1
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1answer
98 views

Apparent Magnitude of First quarter Moon [closed]

Given Apparent magnitude of moon is -12.5. Distance of moon and earth is 384400 km. Diameter of Moon is 31 arcmin. Phase of moon is 0.5. Find the apparent magnitude of first quarter moon.
10
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2answers
2k views

Is there a precise definition of "Supermoon"?

Elsewhere online I keep reading that a supermoon is the situation when full moon coincides with moon perigee. But see this plot from wikipedia Lunar Distance entry The perigee distance varies wildly ...
2
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2answers
165 views

Can we see the south Pole of the Moon standing on North Pole of the Earth

As the Moon's orbit is inclined to Earth's Equator and radius of earth is only 6350Km but Moon is 385000Km away, we should be able to see the south pole of the Moon from below- i.e standing on North ...
25
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3answers
5k views

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 ...
1
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0answers
44 views

Why does Earth have only one moon? [duplicate]

The moon was first formed billions of years ago when a Mars-sized object crashed into Earth. The pieces formed over time to create our moon. Why was only one moon formed? Could Earth have had other ...
14
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5answers
1k views

Using parallax to find distance to the moon

I want to use the parallax method (from scratch) to find the distance between the earth and the moon. To get a significant parallax, I need to choose a large baseline. I live in India and my friend in ...
1
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0answers
53 views

Moon cycles used for gardening & harvesting

I appreciate that this question may deviate from the standard astronomy questions. I have recently read an article that suggest that gardeners, farmers & winemakers etc sometime use the moon's ...
3
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2answers
167 views

What did I photograph around 6 AM on April 27th, 2021? Supermoon plus comet?

Facing SW just before sunrise on April 27, 2021 in Central Florida: The timestamps on the pics start at 6:23 end at 6:27. It was still visible and breaking up like a post launch trail that I would ...
2
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1answer
70 views

What is a "fundamental location", and why is Mosting A defined as one for the moon?

The crater Mosting A was chosen to be the "fundamental location" for the Moon's coordinate system (latitude and longitude). But what exactly is a "fundamental location"? What does ...
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0answers
121 views

What do these coordinates mean: MW - VP101 3° 12' 43.2'' S 5° 12' 39.6'' W?

I have a jacket with a tag that bears the label: MW - VP101 3° 12' 43.2'' S 5° 12' 39.6'' W When I looked it up, I discovered that these are the coordinates of the ...
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0answers
31 views
3
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0answers
51 views

Are interstellar meteorites more common on the moon's polar regions?

Given that the rocks of the solar system mostly travel on the disc, is there any considerable probability that impacts on the moon coming straight up and down can be interstellar rocks? If axis-...
2
votes
1answer
58 views

Lunisolar calendar: what phase was the moon Y years ago on the spring equinox? [closed]

How would I go around answering these questions (e.g., for $Y=10,000$ -- IOW, historical observations are not available and the time is too long ago to rely on a fixed calendar): How many days ago ($...

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