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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The presence of maars on the Moon

Wondering if there's any evidence to date of the existence of maar craters on the Moon? If not, how probable is it that the moon ever supported the necessary conditions for maars to form? A report ...
samiant's user avatar
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6 votes
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What is the relation between the saros (18 years, 11 days, 8 hours) and the period of lunar nodal precession (18.6 years)?

I am wondering. I am sure that they are related. How can we derive one from the other?
Youngsub Yoon's user avatar
5 votes
1 answer
248 views

Will Lunar Months be the same length Millions of Years in the Future?

If I remember correctly, the amount of time it takes for the moon to rotate around Earth is getting longer over time. Is this true, and if so or the opposite is true and a lunar month is getting ...
Dromeoraptor pennato's user avatar
5 votes
0 answers
97 views

Simulate earth, moon, sun constellation with dates

I would like to simulate the three object distance, specifically the distance of the moon to both, sun and earth for further investigation into tide prediction. What would be a good starting point ...
El Dude's user avatar
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How to measure the latitude of the moon?

In the geocentric solar ecliptic (GSE) system of coordinates, the position of the Moon is described by its longitude and latitude. The former is, with great accuracy, the angular distance between the ...
WordP's user avatar
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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 ...
Peter's user avatar
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How can lunar pits be distinguished from craters?

ESA's news En route to exploring lunar caves features the following paragraph: The Moon's surface is covered by millions of craters, but it also hosts hundreds of very steep-walled holes known as ...
B--rian's user avatar
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4 votes
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How much (more or less) of the moon will be visible as it recedes from the Earth?

The Moon is receding from the Earth, at a rate of about 4 cm per year. We can currently see about 59% of the Moon's surface, from the Earth's surface. Will the amount of the Moon's surface we can see ...
costrom's user avatar
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How do I calculate moon phase orientation at any Coordinates given all the necessary data?

I'm having a problem for a couple of days where I'm trying to accurately calculate the phase angle of the moon at any given Coordinates (lon,lat).If I know my current Coordinates, Moon and sun ...
The Oathman's user avatar
3 votes
0 answers
91 views

Sun and moon same angular radius - how unlikely is this?

How many planets do we expect, statistically, in the universe, have a sun and a moon with such a similar angular diameter as we do on earth? How many habitable planets? Is it possible to calculate ...
Rabbi Kaii's user avatar
3 votes
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90 views

Confusion about the position of lunar perigee

I'm using python pkg named astronomy-engine.First,I find 2 consecutive perigee times of moon. ...
AInseven's user avatar
3 votes
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172 views

Determining the distance to the Moon from parallax using the following information

How could I determine the distance from the Earth to the moon by using the method of simultaneous parallax? I know the right ascension and declination as seen from two different points on earth. I ...
Luis Sarmiento's user avatar
3 votes
0 answers
179 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. ...
J. Doe's user avatar
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3 votes
0 answers
59 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-...
bandybabboon's user avatar
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What's the first written record of the moon being tidally locked to the earth?

I couldn't find references as to who first noticed (wrote down) that the moon was tidally locked to the Earth. This, to me, doesn't seem obvious from first glance, and looks like something only found ...
Yuri-M-Dias's user avatar
3 votes
0 answers
105 views

Any pictures showing difference in moon between southern and northern observers?

Since observers in different parts of Earth will be observing the moon at slightly different angles relative to its (choose reference vector: north pole, origin of latitude longitude position, ...
NeutronStar's user avatar
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3 votes
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Why weren't Lunar meteorites identified until 1982?

According to Wikipedia the first meteorite of Lunar origin wasn't identified until 1982. Today 306 Lunar meteorites have been identified. Why weren't they identified as Lunar already a decade earlier,...
LocalFluff's user avatar
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How do I deduce my latitude and longitude from N obervations of occultations from the same place?

I think it would be an interesting exercise to measure the latiude and longitude of my house using N occultation timings. I would like to see how precisely I can measure it using that technique, and ...
John's user avatar
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3 votes
1 answer
114 views

How can I compute the shape and orientation of the crescent for a given time and geographic location using data from the JPL Horizons?

I can compute the following data for the Moon for a given time and geographic location using the JPL Horizons system: Apparent RA & DEC Apparent azimuth & elevation (AZ-EL) Target range & ...
Klaus Rohe's user avatar
3 votes
1 answer
648 views

Is the high-low tide difference greater, on average, at new moon, full moon, or neither?

The difference between high tide and low tide peaks when the moon is full and also when the moon is new. At both of these points in the lunar cycle, the tides are known as "spring" tides. On ...
ool's user avatar
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2 votes
0 answers
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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 ...
Hunter's user avatar
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2 votes
0 answers
106 views

Which conditions / situations / place / moment is there a purple moon in the sky in?

According to this A purple moon? In March 12, 2017 there was a purple moon somewhere , "just risen, color altered red moon". I've seen yellowish, redish moons, but I've never seen a purple ...
Pablo's user avatar
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2 votes
0 answers
103 views

True node (NN) calculation .. off by 10 seconds

...
dimitri33's user avatar
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2 votes
0 answers
96 views

Moon position differences on JPL Horizons, GMAT, Skyfield (using DE421)

I found a relevant difference in the positions for the Moon when calculating its Geocentric position with GMAT and Skyfield (https://rhodesmill.org/skyfield/), in both cases with JPL DE421. ...
Thibault's user avatar
2 votes
0 answers
55 views

From a given latitude on Earth, how to calculate the number of days in a year when the moon is lit on the bottom?

From a given latitude on Earth, is it possible to calculate the number of days in a year when there is a wet moon , that is when the moon is lit on the bottom? If, for example, I want to do the ...
William's user avatar
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2 votes
0 answers
503 views

tool to calculate moonrise/moonset and moon phase for any date for any location

I have googled for such a solution but I have not found anything substantial: I found one website but it was someone's side hobby so my confidence in it is low. Thankfully, I have discovered ...
Bob's user avatar
  • 213
2 votes
0 answers
76 views

Besides Luna, are there any models of how moons become spherical and round?

Question Given the theorized exceptional formation of Luna, (Giant-impact Hyphothesis, Wikipedia), are there any similar animated models of how the other, much smaller, moons in our solar system ...
elika kohen's user avatar
2 votes
0 answers
152 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 ...
LoveForChrist's user avatar
2 votes
0 answers
107 views

Moon's and nodes' inclination to the Invariable plane

Moon is inclined to the ecliptic 5.14 degrees. Earth's inclination to the invariable plane is 1.57869 degrees. What is the Moon's, and node's inclination to the invariable plane? Since the Moon has an ...
Majoris's user avatar
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2 votes
0 answers
257 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 ...
Jee's user avatar
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2 votes
0 answers
2k views

Calculating the position angle of the moon (the rolling back and forth)

I have been watching the the NASA Moon Phases Video of the year 2020. Pretty much everything makes sense and I know how to calculate it including the moon phases, declination, azimuth, apogee and ...
The Oathman's user avatar
2 votes
0 answers
31 views

Moon rotation tidal braking

Do we know if the moon had an initial rotation or did it coalesce tidally locked. If it had an initial rotation how long would it take to become tidally locked?
user36138's user avatar
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2 votes
0 answers
163 views

Field rotation and observing the moon

For stars, field rotation can be accounted for with an equatorial mount aligned with the Earth's axis and turning at the correct rate. Since the Moon's orbit is on a different axis then the Earth's ...
jeffry7's user avatar
  • 71
2 votes
0 answers
55 views

Speed of Moonrise relative to fixed point on ground

Due to the curvature of the earth, and the way the moon interacts with the atmosphere (especially close to the horizon), is there a known function that describes the speed of the moon relative to its ...
nick_halden's user avatar
2 votes
0 answers
100 views

Where on Earth can moon rise on the meridian?

Somewhat related to this my picture showing only diurnal motion but Moon—seen from Earth—has a rapid motion with respect to the inertial celestial sphere, unlike stars and planets. Its motion relative ...
Incnis Mrsi's user avatar
2 votes
0 answers
100 views

Polar circle for the moon

The polar circle is the limit for how far north or south the sun will shine 24h. But is there a similar limit for the moon?
Torstein Gjerde's user avatar
2 votes
0 answers
92 views

calculating paralax angle from observations

Say I have 2 records, in horizontal coordinates of the azimuth ($A_z,A_z^{'}$) and altitude ($\alpha,\alpha^{'}$) of the moon at the same time in two different places that are $\theta$ degrees apart (...
cal's user avatar
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1 vote
0 answers
15 views

Has anyone attributed a specific Baily's bead to a specific feature on the Moon? If so, when was this first done?

From Wikipedia's Baily's beads: Lunar topography has considerable relief because of the presence of mountains, craters, valleys and other topographical features. The irregularities of the lunar limb ...
uhoh's user avatar
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1 vote
0 answers
49 views

What Exactly Causes Lunar Nodal Precession?

I'm trying to understand what exactly causes lunar nodal precession. Based on this article, my understanding is that precession of the plane of the moon's orbit is what causes the motion of the Moon's ...
Stephen W.'s user avatar
1 vote
0 answers
43 views

Is the "light-time" correction for the Moon's position in Meeus "Astronomical Algorithms" putting the Moon in inertial position or apparent position?

Originally posted on Space Exploration SE, I was encouraged to post it here. I'm looking at the second edition of Meeus's "Astronomical Algorithms," chapter 47, "Position of the Moon.&...
NeutronStar's user avatar
  • 2,663
1 vote
0 answers
22 views

Geocentric position of lunar ascending node relative to the true equator and equinox of date, using skyfield

The following is what I'm doing currently. Am I missing something here? I'm unsure if I am converting in and out of Skyfield objects correctly, and there is any unaccounted for behavior i'm not seeing ...
Hunter's user avatar
  • 321
1 vote
0 answers
89 views

Kepler's description of lunar mountains before telescope

This question Why is the lunar relief not visible in photographs of solar eclipses? Reminds me of something that I remember that Johannes Kepler wrote. When telescopes discovered mountains and ...
M. A. Golding's user avatar
1 vote
0 answers
66 views

How to calculate the Topocentric Elongation of the Moon?

I was trying to calculate the Topocentric Crescent Width and I found this answer, How to calculate Topocentric Crescent Width and Moon Radius/Semi-Diameter? However, I am missing the Topocentric ...
Jari's user avatar
  • 11
1 vote
0 answers
50 views

Looking for data and models for events of Sun and Moon apparent motion in distant past?

For the current Julian Era (from 1, 1, 4713 BCE to modern day), I am looking for a raw data tables or a model that allows to predict the following events related to apparent motion of Sun and Moon: ...
Suiinditor Impudens's user avatar
1 vote
0 answers
67 views

Is there a specific area on the far side of the moon, directly below the L2 Lagrange point in the Earth/Moon system?

It seems like there should be, and if so I wonder how large an area it is, if it changes size over time, and if it moves or wobbles in some way. On the latst point, I imagine it would certainly wobble ...
Nick Codignotto's user avatar
1 vote
0 answers
322 views

JPL Ephemeris or Skyfield - how to get moon phase percentage (not illumination percentage)

I know how to use JPL's Horizons to get moon illumination percentage but I noticed that even at new moon, the illumination never goes to zero: ...
Bob's user avatar
  • 213
1 vote
0 answers
60 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 ...
ALiCe P.'s user avatar
  • 1,017
1 vote
0 answers
70 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 ...
Will's user avatar
  • 11
1 vote
0 answers
1k 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 ...
Phiteros's user avatar
  • 3,166
1 vote
0 answers
30 views

What replenishes the lunar atmosphere?

It is often said that the Moon doesn't have an atmosphere. But there is an envelope of gas surrounding the Moon, albeit a thin one, so the Moon has at least an exosphere. The Moon doesn't have its own ...
usernumber's user avatar
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