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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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6 votes
1 answer
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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 ...
Fattie's user avatar
  • 946
1 vote
1 answer
84 views

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 ?
moontracker's user avatar
7 votes
2 answers
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 ...
Curious Layman's user avatar
3 votes
1 answer
135 views

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?
Vladimir Orlov's user avatar
0 votes
0 answers
35 views

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 ...
DanceroftheStars's user avatar
1 vote
0 answers
46 views

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 ...
Curious Layman's user avatar
0 votes
1 answer
43 views

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.
Niamat Sandhu's user avatar
0 votes
0 answers
40 views

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?
Vladimir Orlov's user avatar
3 votes
1 answer
145 views

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
SupaD75's user avatar
  • 41
1 vote
0 answers
49 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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16 votes
2 answers
5k views

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 ...
Curious Layman's user avatar
0 votes
0 answers
32 views

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 ...
Curious Layman's user avatar
0 votes
0 answers
32 views

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 ...
Curious Layman's user avatar
0 votes
0 answers
24 views

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 ...
Curious Layman's user avatar
0 votes
0 answers
31 views

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 ...
neubert's user avatar
  • 195
4 votes
0 answers
95 views

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 ...
Rabbi Kaii's user avatar
1 vote
1 answer
100 views

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 ...
wberry's user avatar
  • 349
3 votes
1 answer
143 views

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 ...
Cingonius Varro's user avatar
2 votes
1 answer
105 views

Earth-Moon receding-approaching cycle?

I made the following question in an another more informal forum of discussion on physics: My question comes after reading this article: https://www.coastreporter.net/in-the-community/the-moon-is-...
vengaq's user avatar
  • 937
0 votes
0 answers
52 views

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....
dimitri33's user avatar
  • 167
1 vote
1 answer
74 views

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
noob_watchmaker's user avatar
2 votes
2 answers
88 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. ...
Stephen W.'s user avatar
1 vote
0 answers
61 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
8 votes
3 answers
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?
Kala Bicho's user avatar
-1 votes
1 answer
184 views

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 ...
Vladimir Orlov's user avatar
2 votes
0 answers
37 views

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
  • 321
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
  • 2,673
1 vote
0 answers
24 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
6 votes
1 answer
128 views

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 ...
MiltonTheMeme's user avatar
2 votes
1 answer
121 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 ...
Albert's user avatar
  • 2,102
1 vote
0 answers
90 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
6 votes
2 answers
3k views

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 ...
Vladimir Orlov's user avatar
9 votes
1 answer
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 ...
ksousa's user avatar
  • 1,171
7 votes
1 answer
170 views

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 ...
David McKee's user avatar
1 vote
0 answers
67 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
3 votes
2 answers
141 views

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 ...
user267545's user avatar
10 votes
3 answers
801 views

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 ...
Zac Warham's user avatar
1 vote
1 answer
130 views

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 ...
dimitri33's user avatar
  • 167
1 vote
0 answers
51 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
5 votes
2 answers
560 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 ...
tockpeas'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 votes
1 answer
140 views

Earth and the Moon Question [closed]

(For the purpose of this question, I will refer to Earth's Moon as Luna to keep it separate from the general term of 'moon') I know the IAU has been hedgey about giving an official definition of what ...
user53218's user avatar
0 votes
3 answers
6k views

Is it possible to view the sun and moon in the sky at the same time?

I'm writing a story. I want my ending to have the sun and moon visible in the sky at the same time. It is symbolism for the larger story. Is this possible? I have tried searching and can't find ...
CJ Winters's user avatar
4 votes
4 answers
5k views

What is the ring of light around the moon and which star seen near it?

In this amatuer photograph, the following are to be noted: There is a faint ring of light around the moon. What is the distance we see this at. From the ground it looks like a hundred meters. There ...
Nick's user avatar
  • 239
3 votes
3 answers
1k views

Celestial "orbits"

I heard that we're losing our moon, its slipping away from us in such tiny imperceptible steps that we don't notice any significant change even over kiloyears. The same must apply to planets, inching ...
Hudjefa's user avatar
  • 353
3 votes
0 answers
91 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
1 vote
1 answer
137 views

sideways crescent moon but also no moon somewhere else?

I live in Sumter, South Carolina and the moon looked like a crescent moon but sideways like a bowl. But when I told my friend to look at the moon they couldn't find it and they live in Buffalo, New ...
Cakebandit06's user avatar
11 votes
1 answer
5k views

Why did Theia create only one moon if it struck Earth?

If I dropped a heavy ball into some magma it would splash all over the place. So why would Theia create only one large drop of liquid (the moon) and if it impacted the Earths mantle (Bits of Theia ...
user avatar
3 votes
1 answer
160 views

Could a Martian observer witness the Moon's formation with naked eye?

Suppose a human observer was standing on Mars during the early Solar System, looking up into the night sky, in the approximate direction of the young Earth, as the Theia planet hypothesized in the ...
Ezra Bailey's user avatar
6 votes
1 answer
1k views

How can the new moon set before the sun, as will happen in some locales on November 13, 2023?

I have somewhat of an interest in sighting the new moon. I recently heard a lecture by someone who had written a program to provide the conditions for the first new moon sighting for any location for ...
Michael Appel's user avatar

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