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].

39 questions with no upvoted or accepted answers
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6
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0answers
206 views

When the Moon formed and early on, did it orbit over the Earth's equator?

Or was it always at about 5.14 degrees inclination or has the inclination changed over time? See diagram. James K's answer to this question got me thinking about this, and I don't mean to call him ...
6
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1answer
315 views

The most feasible hypothesis about Theia

The formation of the Moon had many hypothesis over the years, most of them involving a Mars-sized body called Theia, which presumably collided with the Earth. But even within the Theia hypothesis, is ...
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Is the Ordovician meteor event detectable in the lunar cratering record?

Approximately 468 million years ago there were a large number of L-chondrite meteorites falling to Earth. This is called the Ordovician meteor event and was probably the result of a large collision in ...
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58 views

How open is China in sharing data from the Chang'e 4 mission?

It's really good to see that man (well, machine) has gone back to the moon again. Chang'e 4 is studying potential mantle material from the lunar depths and will be conducting radio astronomy in ...
5
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50 views

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?
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56 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 ...
4
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47 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 ...
4
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0answers
940 views

What is the highest resolution image of the moon taken from Earth's surface?

According to this article: https://www.theguardian.com/science/2018/jul/26/star-spotted-speeding-near-milky-way-black-hole-for-first-time the Very Large Telescope is "powerful enough to see a tennis ...
4
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97 views

How fast was the Earth spinning directly after the Moon formed?

I understand the Moon was perhaps five Earth radii away when it first formed (assuming it was formed by a giant impact of a Mars-sized body), and Earth has since transferred its rotational energy into ...
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65 views

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 ...
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74 views

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 ...
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71 views

What is the apparent magnitude of the faintest stars visible during a full moon?

Assuming the viewer is far from any light pollution, it is a cloudless night, and humidity is very low. What is the faintest apparent magnitude of stars visible to the naked eye during a full moon (...
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34 views

Why would the Chang'e-4 lander find lunar far side temp. “colder than scientists expected”, when the LRO has already been taking thermal readings?

In January, the Chinese probe lander Chang'e-4 was was announced to have found temperatures dipping lower on the far side than expected ("Chinese rover finds lunar nights 'colder than expected'" by R. ...
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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, ...
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152 views

Are Saros series separated by “40” in numbering related in any way?

Can anyone help with this question? My question arose from an eclipse related observation that I made while looking into lunar Saros series 129. It is the Saros series number for the lunar eclipse ...
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77 views

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 ...
2
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42 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 ...
2
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171 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 ...
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28 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?
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61 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 ...
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155 views

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 ...
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44 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 ...
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77 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 ...
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57 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?
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62 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 (...
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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,...
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165 views

Observed sun/moon rise/set times to nearest second?

Where can I find a list of observed (not computed) sun/moon rise/set times to the nearest second, along with the location (latitude, longitude, altitude [or enough information to find these three ...
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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 ...
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50 views

Moon Photo from Apollo 12 mission

Can anyone explain why the Moon looks so small and dark in photos taken from cislunar space during the Apollo 12 mission? AS12-53-7887 found at https://www.lpi.usra.edu/resources/apollo/frame/?AS12-53-...
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33 views

Do contact binaries such as Ultima Thule affect our current theories on how the Moon formed?

While I was reading about Ultima Thule, I was wondering if the discovery of contact binary objects had any effect on our current theories of how the Moon formed?
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114 views

Moon equatorial coordinates

It took some effort, but in the end, I successfully calculated the geographical point of the Sun. I assumed that I could do the same for the Moon. My plan is: Find RA and declination of the Moon ...
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37 views

Lunar illumination (percentage) data on an eclipse day needed

I am looking for the information on the percentage illumination of the moon during the different stages of a total lunar eclipse. Is there a database from where I can acquire information of lunar ...
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87 views

what is the net effect of nodal and apsidal lunar precession?

In apsidal lunar precession, the moon's elliptic major axis precesses eastward and completes one revolution eastward in 8.85 years. Because the orbit is inclined relative to the ecliptic, basic ...
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51 views

What does Ptolemy mean by “a line drawn from the centre of the earth through the centre of the moon to a point on the ecliptic”

This is from a translation of Ptolemy's Almagest Hence it necessarily follows that the straight line draw n from the centre of the earth (which is the centre of the ecliptic) through the centre of ...
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72 views

Why do I need to know about moonphase?

I just watch an interesting video about Moonphase watch. mmm... but why do I need to know about moonphase anyway, I just can't think of any practice for the moonphase indicator on the watch?
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165 views

Angles in Moon, Earth and Sun system

Consider the vector positions of the center of mass of Moon, Sun and Earth, $\vec{r}_{\rm M}$, $\vec{r}_{\rm S}$, $\vec{r}_{\rm E}$, respectively, in a given reference frame. Consider: the angle ...
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62 views

How close must a full moon be to become a supermoon?

According to this answer there is a scale of super moons depending on how close the full moon(henceforth anti-sol) is to perigee. So how close to anti-sol does the moon's perigee need to be to be ...
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17 views

When was the variation of apparent diameter of the moon first measured?

The orbit of the Moon around the Earth isn't quite a circle. Since distance between the Earth and the Moon changes over time, the apparent diameter of the Moon also varies very slightly. With a ...
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50 views

Astronomical events and Celebrations

In the past people celebrated important astronomical events and some of those events are still celebrated in some cultures and traditions. For example: March/September equinox, New Moon, Winter/...