# 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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1 vote
66 views

### How quickly would these changes happen if the moon were to suddenly disappear?

There's a lot of articles and videos on the topic of what would happen if the moon were to suddenly disappear. Two consequences that seem to come up often are an increase in variation of Earth's axial ...
125 views

### Is it cheaper to mine raw materials in Antarctica or on the Moon?

A colleague in school said that it is cheaper to mine resources on the moon and bring them to earth than to do the same in Antarctica because it is so cold in Antarctica. Is that true?
1 vote
52 views

### calculate declination and right ascension with limited information

I'm trying to make a game with high accuracy moon position so I followed some equations on geoastro.de Basics of Positional Astronomy and Ephemerides and with some help from the questions answers, I ...
62 views

### How to calculate moon's distance and parallax in it's altitude

I'm trying to calculate moon's parallax in it's altitude depending on the day I need and I followed this formula by geoastro.de Basics of Positional Astronomy and Ephemerides but I need to calculate ...
142 views

### Why does the moon have a similar angular velocity around earth as the sun has around its centre?

Is this coincidence or something more? Did the moon and core form in similar ways?
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### Wrong results of calculating moon's altitude and azimuth

I'm trying to calculate moon's altitude and azimuth and I followed this formula by geoastro.de Basics of Positional Astronomy and Ephemerides There is an example to test the formula at the end of the ...
1 vote
70 views

### How does azimuth of moonrise/moonset vary by longitude?

I found a useful formula for calculating the azimuth of moonrise/moonset, which can be found in this post: How does moonrise/moonset azimuth vary with time? However the formula refers to the fixed ...
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### Have micrometeoroids been observed impacting the moon's surface?

Have any cameras on the moon's surface directly observed micrometeoroid (or larger!) impacts? Presumably small craters form when impacts occur and information could be gleaned from observing the ...
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### Has earthshine in fact increased since lights (say 1900); that is to say can we measure or has there been a measurable increase? What are the numbers?

Three questions, How would, or how is commonly, earthshine best stated (absolute magnitude, overall watts from the lunar surface, or?). (Further, since the moon is irregularly shiny is it measured ...
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1 vote
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### What is the position directly below the moon on the earth called - is it the lunar nadir?

What is the position directly below the moon on the Earth called - is it the lunar nadir or something else ?
2k views

### What can be learned from viewing the sun on earth during a total eclipse that cannot be studied by spacecraft in orbit?

I understand that total eclipses are a fantastic time to study the sun's corona, and the reason for this is because the much brighter photosphere is blocked by the moon. But, couldn't the Parker solar ...
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### What is the longest time the Moon can stay in the sky?

It is known that in northern latitudes the Moon, like the sun, can remain in the sky for a long time, a week or more. What is the longest time the Moon can stay in the sky?
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### How to find Nodal Precession of a moon

So, I found a formula for finding the Nodal Precession rate of a satellite here https://en.m.wikipedia.org/wiki/Nodal_precession But the thing is, when I pop in all the numbers in the formula on ...
1 vote
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### What is the difference between a solar eclipse's (a) magnitude and the (b) moon/sun size ratio?

After watching a Smarter Every Day 2 YouTube video featuring Gordon Telepun, I purchased his ebook Eclipse Day 2024 and More off the Google Play store. In the book, he has a link to Xavier Jubier’s ...
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### Moon observations at different places on the earth

How does look like the rising then attaining the maximum altitude and then finally setting of the moon when seen from either of the poles of the earth.
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### Why does the projection-motion of the moon on the earth's surface have the shape of a sinusoid?

Why does the projection-motion of the moon on the earth's surface have the shape of a sinusoid? How does this fit with the tellurium model?
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### Are these craters on the moon during eclipse

can somebody confirm that what im looking at are craters on the moon? This was taken during the 2024 eclipse from illinois with my S24 ultra iso250 115mm -2.0ev F3.4 speed 1/10000. thanks
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1 vote
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### 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 ...
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### Why is there a year 1 B.C., a year 0, and a year 1 A.D. in NASA’s Five Millennium Canon of Solar Eclipses?

I was looking through NASA’s Five Millennium Canon of Solar Eclipses, and I am really confused by the fact that there is a year -1, 0, and 1. I was always taught that there was no year 0, that we just ...
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### Is there a known magnitude of the sun that needs to be covered for the diamond ring effect or Bailey’s beads to occur?

During a total solar eclipse, there is this brief, roughly 1-20 seconds during which some absolutely incredible, indescribable phenomenon occurs. It was the most beautiful thing I have ever seen. They ...
• 1,170
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### Is it possible for both transition points in a hybrid eclipse to occur so close together they can be seen from the same spot on earth?

There are 4 categories of eclipses. There are partial, annular, total, and hybrid eclipses. In a partial eclipse, part of the moon covers the earth casting its penumbra on earth. Judging from my ...
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### Is there any way to know how much time of totality is experienced during a hybrid eclipse in NASA’s 5 Millennium Canon of Solar Eclipses?

I was just looking through NASA’s 5 Millennium Canon of Solar Eclipses. It’s really a fantastic list, having the max time of totality and all. I was trying to figure out what the maximum amount of ...
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### upper and lower bounds for how big the moon could be whilst still letting you see the sun's corona during totality

It's often said that the reason total eclipses are possible is because altho the moon is 400 times smaller than the sun it's also 400 times closer than the Sun. But it occurs to me that the apparent ...
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### Sun and moon same angular radius - how unlikely is this? [duplicate]

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 ...
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1 vote
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### Ancient adjudication of the new moon from witness testimony

The ancient method of certifying the new moon in the Land of Israel in ancient times is described in Mishnah Rosh Hashanah 2:6. Witnesses would come to Jerusalem and testify before the Sanhedrin that ...
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### Is the Moon really oscillating around its orbit as seen from Earth?

While simulating today's eclipse, I see something I have never noticed or learnt: Stellarium shows an oscillation of the Moon's trajectory around its orbit as seen from Earth. Is it real or a ...
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### How to find the Moon's node longitude crossing

Yes, I asked this in the past but I got sidetracked and did other things. Now my question is, can one find the exact time when "north node" reaches a certain longitude? I am looking for 15....
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1 vote
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### How can I plot a rotary cam for the equation of time? [closed]

I'd like to use Solidworks to create a cam (peanut looking) for computing the equation of time in a pocket watch. Would appreciate any point to the right direction or advice. Audemars Piguet EoT
97 views

### Is the Moon's orbital plane angle relative to the ecliptic constant?

I've come across a number of sources (example) saying some variation of this: The moon's orbital path around Earth is tilted by 5.1 degrees with respect to the orbit of the Earth around the sun. ...
1 vote
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### 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 ...
4k views

### Can a lunar eclipse happen at night and be followed by a solar eclipse the next day?

Is it possible for a lunar eclipse to occur during the night and then be followed by a solar eclipse the next day? Could these two events happen consecutively, and if so, how rare is this phenomenon?
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### Why is the lunar disk completely black during solar eclipses?

I noticed that during solar eclipses the lunar disk looks completely black, it is impossible to see any relief details on it. At other times, the unlit part of the Moon is quite clearly visible. An ...
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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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1 vote
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### 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.&...
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1 vote
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### 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 ...
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### Doesn't the moon actually make asteroid impacts on Earth more likely?

So the moon adds to the total mass of the Earth-Moon system so together there is more mass so then there should be more gravity due to the total system and the moon is small relative to how much ...
130 views

### Details of the Moon's night photographed in a total solar eclipse

I didn't know that in photographs of total solar eclipses you could see details of the Moon's night. To my surprise, look at this beautiful photo of the solar eclipse of 2024/04/23 taken by amateur ...
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1 vote
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### 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 ...
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### Why is the lunar relief not visible in photographs of solar eclipses?

I looked at a lot of high-quality images of solar eclipses and noticed the following thing: In all the photographs I've seen, the lunar disk has a completely clear outline, in which it is impossible ...
2k views

### Had Earth lost the Moon early, would we be able to determine it once had a companion?

Despite the Solar System looking quite stable, clockwork-like on human timescales, to such a degree the movement of its members is used to track time and make calendars since antiquity, it is pretty ...
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### Why are lunar craters preferentially north-south aligned?

Loading the dataset from Robbins 2018, A New Global Database of Lunar Impact Craters >1–2 km: 1. Crater Locations and Sizes, Comparisons With Published Databases, and Global Analysis which I ...
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1 vote
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### 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 ...
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### Will the Moon recede far enough that the Earth-Moon barycenter lies outside of Earth's radius before the Sun becomes a red giant?

As most people know, the Moon is receding from Earth at a rate of a few centimeters per year. This rate is not constant; as the Moon gets farther away, the tides it raises will be weaker and thus will ...
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### Proportion of Lunar Fraction in a Year

I grabbed a year of lunar fraction data from the USNO and binned the counts to find the shape of the curve as below My understanding of lunar fraction was that 0.5 does not distinguish between the ...
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### calculating apogee and perigee for moon and sun

The perigee does not necessarily happen when we have a full moon, using swevents we can easily determine the moon phases. Now can we use python to determine when ...
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### 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: ...
564 views

### Sky illumination based on moon phase and altitude

Does anyone know if there has been any work in determining the impact of the moon on sky brightness based on phase, moon altitude (including below the horizon), location altitude, humidity, etc? This ...
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