Questions tagged [moon]

For questions that relate to Earth's natural satellite.

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Im trying to find a formula to calculate Earths radius/ diameter by horizontal cross section to see what effect that has on size of the moon appears

Todays Biue Moon (that wont happen again til 2036) is the biggest brightest and closest the moon is to Earth Im trying to determine how it appears at ones given latitude.Obviously the closest one is ...
Frederick Frank's user avatar
4 votes
1 answer
65 views

Relay structures in Rupes Recta

Rupes Recta is a 110km long normal fault on the Lunar nearside. It appears to contain features that resemble terrestrial relay ramps. Is this the case or is it something else?
Andykins 's user avatar
4 votes
1 answer
104 views

Why was quartz not a major product of the Lunar Magma Ocean?

Fractional crystallisation generally makes magma more silicic. Why was a substantial quartz layer not a product of the stratification of the Lunar mantle?
Andykins 's user avatar
1 vote
0 answers
67 views

Reason behind diurnal tides

I know that an area has a diurnal tidal cycle if it experiences one high and one low tide every lunar day. Many areas in the Gulf of Mexico experience these types of tides. I read that: Diurnal tides ...
pacman's user avatar
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8 votes
1 answer
975 views

Does the Moon affect earthquakes?

Does the Moon, through factors like its location (if it is at an apsis i.e closest point or furthest point in its orbit) or some changes in density, affect earthquakes on the Earth? Earthquakes are a ...
user avatar
3 votes
1 answer
246 views

What would be the effect of a geostationary moon?

What kinds of differences from our Earth would we see with a moon in a geostationary orbit over the equator? Assuming the gravitational pull is roughly the same as it is with ours (my back of the ...
Sarah's user avatar
  • 133
2 votes
0 answers
26 views

Calculate original volatile content of a degassed mineral

A lunar apatite sample has a relatively low OH content of 5 ppm, but a an elevated D𝛿 of 11,000‰ (vs. SMOW). Assuming that water had an original figure of around -100‰ or so, how do I estimate the ...
Andy's user avatar
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6 votes
1 answer
93 views

Why is the Lunar crust anorthite?

The primordial Lunar crust is mostly calcic plagioclase. However, why did the Lunar Magma Ocean produce so much anorthite, why not a feldspar of a different composition, like albite or orthoclase for ...
Andy's user avatar
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1 vote
1 answer
410 views

What does fugacity mean in the context of geology?

I am reading about water in the Lunar mantle, however it mentions fugacity a lot. What does it mean in this context?
Andy's user avatar
  • 21
4 votes
1 answer
1k views

What is the difference between a depleted mantle, and a fertile or enriched mantle?

In a paper about the interior of the Moon, it references depleted mantle sources and enriched mantle sources. Sometimes the latter is referred to as 'fertile'. What is difference between the first two?...
Andy's user avatar
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2 votes
0 answers
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What would the approx. min and max temperatures be for Snowball Earth with no atmosphere?

I saw a similar previous question on this website about the temperature of the Earth with no atmosphere. It sounds like if the Earth did lose its atmosphere we’d end up with either Snowball Earth or ...
Gary45226's user avatar
2 votes
1 answer
277 views

What is the elevation angle of sun at lunar poles?

The Moon's orbital plane is inclined by about 5.1° with respect to the ecliptic plane, whereas the Moon's equatorial plane is tilted by only 1.5°.
Ananya Srivastava's user avatar
1 vote
1 answer
45 views

Does the Sun and Moon basically appear to "move on the sky" identically regardless of location and date? [closed]

For a long time, I've been trying to use Stellarium (simulation) and many visualizations and animations in order to get a good idea of how the Sun and Moon move across the sky, as seen by a human from ...
MooMoo's user avatar
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6 votes
1 answer
839 views

How to make a Python function return the Moon's gravitational force (acceleration) to calculate orbits?

The Space SE question How much does it cost to land on a lunar mascon? includes the background information below. I am sure it's not too hard to find a link where spherical harmonic coefficients for ...
uhoh's user avatar
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3 votes
1 answer
127 views

How do they get "deep lunar mantle" samples?

Phys.org's Study suggests Earth and Moon not identical oxygen twins says They found that the oxygen isotopic composition varied depending on the type of rock tested. This may be due to the degree of ...
uhoh's user avatar
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2 votes
2 answers
245 views

What has been the influence of the moon on Earth's temperature?

What proportion of Earth's internal heat is generated by tidal flexion as a result of the orbiting moon, and would it have been significantly greater four billion years ago when the moon was closer? ...
Michael Walsby's user avatar
10 votes
6 answers
5k views

Can living where (rare) earth magnetic ore is abundant provide any protection from cosmic radiation?

Can living in a region that is rich in (rare) earth metal that has an inherently strong magnetic field provide any protection from cosmic radiation? Where are the strongest magnetic field other than ...
Muze's user avatar
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5 votes
1 answer
686 views

How much energy does the Moon transfer to the Earth, does this affect the Earth's surface temperature?

I'm wondering by how much the gravitation effects, tides etc caused by the moon (and other energy such as moonlight IR) increase the surface temperature of the Earth. So how much warmer than the ...
Andy's user avatar
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1 vote
0 answers
88 views

What are "young thrust faults" and how does one identify them on the Moon?

The abstract of the new Nature Geoscience paper Shallow seismic activity and young thrust faults on the Moon reads: The discovery of young thrust faults on the Moon is evidence of recent tectonic ...
uhoh's user avatar
  • 7,128
8 votes
1 answer
69 views

Is moonlight a significant condition for making life possible on earth?

We know of course that light from the sun is a fundamental component to making life possible on earth because of the energy it provides. Does the light that is reflected off of the moon make a ...
Josh Withee's user avatar
3 votes
0 answers
337 views

Why is the night very bright in the Himalayas?

Some years ago I had the chance to climb the Himalayas. Not the Everest of course, but the Annapurna Base Camp which is about 4km above sea level. During the night of the stay I went out to do some ...
Chaffee's user avatar
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6 votes
5 answers
382 views

Which Earth minerals would Moon colonists miss the most?

In my science-based novel, Moon colonists need to return to Earth to collect some rare or absent mineral(s) Ideally, something they could derive from seawater. Which minerals might they be...?
Bob Goddard's user avatar
3 votes
1 answer
62 views

Moon tilt against the horizon in a single day

Where I can find a graph of the apparent rotation of the illuminated portion of the moon against the horizon in a single day? And is there a place where I can read about all the variations which ...
peter's user avatar
  • 31
8 votes
1 answer
763 views

How come the tide is low when the moon is high in the sky

Happily spending my holidays in the Fiji Islands, I noticed a couple of days ago that when the moon was very high in the sky (my shadow was maybe 0.5-1m long) the tide was low. That really puzzled me....
Nodjo's user avatar
  • 83
24 votes
1 answer
15k views

Why were both the sun and the moon red today?

Today was a normal day, except the sun and moon colors were strange. After 5pm, the sky was covered with cirrostratus-like translucent clouds and the sky was a blend of blue and grey. Everything ...
KKZiomek's user avatar
  • 557
1 vote
2 answers
12k views

How is it possible that only the bottom half of the moon was showing?

A few months ago I was in car and noticed moon. You could see bottom half (in crescent shape) but not top half. How is this possible to look up into night sky and see only bottom half of moon?
John's user avatar
  • 11
-4 votes
1 answer
110 views

What 'time of day' did the heavy bombardment period begin? [closed]

In assigning serial definitions to the stratification of lunar regolith with precise ETA of first impact; what year, month, day and time did the heavy bombardment period begin?
user8320's user avatar
3 votes
1 answer
2k views

How much energy released by the Theia-Gaia impact?

I read somewhere that the Chicxulub impact released the energy equivalent of anywhere from 100-300 teratons of TNT. That's an impressive amount of energy. Assuming a head on collision (according to ...
x0a's user avatar
  • 133
3 votes
3 answers
1k views

Why are there craters on the moon?

The Earth's moon is in synchronous rotation around Earth. The question: Why are there craters on the lit side of the moon and the dark and of which are not parallel with crater schemes on Earth?
user avatar
5 votes
1 answer
3k views

What is the difference between lunar and earth soil

I know that the moon has lunar regolith and earth has earth soil, but what is the difference between them?
MathWA wenti's user avatar
4 votes
1 answer
2k views

How often do king tides (perigean spring tides) occur?

Recently, there has been a lot of information about "King Tides" (i.e, perigean spring tides) on the news with a number of groups relating the peak king tide to future normal conditions (2050) under ...
arkaia's user avatar
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3 votes
0 answers
64 views

What would be characteristic time of the escape of an 1atm air (or oxygene atmosphere) from the Moon?

(related question) I am thinking on the Moon if it would have an oxygen atmosphere. What would be the characteristic time of its escape? Although the Moon has a much lower escape velocity as the ...
peterh's user avatar
  • 660
6 votes
1 answer
145 views

What is the characteristic time of the loss of the Earth atmosphere, how can it be calculated?

Somewhere I've read it is in the order of some tens of billions of years, but unfortunately I can't find any reference with it in Google. I suspect, the losses are coming mainly from analyzing the ...
peterh's user avatar
  • 660
8 votes
1 answer
217 views

Melting basalt on the lunar surface - what would the resulting material be like?

The idea is to melt the fine-grain portion of basalt regolith using a large Fresnel lens, and let it cool to a solid. The lens would track along a tamped bed of material leaving a molten puddle ...
kim holder's user avatar
3 votes
1 answer
2k views

How much do tides affect earth's rotational velocity?

Many of us are familiar with an exaggerated picture of the Moon's effect on Earth's tides: Since the Earth is not uniformly covered with water, however, I imagine that the tidal effect will depend on ...
Ben Sandeen's user avatar
4 votes
2 answers
6k views

Can the moon shadow angle change?

I've got an argument with a mate. He thinks that the moon shadow angle can change from night to night. For example, one night, the near side of the moon is half black/white, black side on top, white ...
Ant's user avatar
  • 143
0 votes
2 answers
1k views

What is the Moon's distance from viewer at horizon?

From a viewer's standpoint, when the moon starts to rise at the horizon, is the moon at the furthest distance from the viewer visually? The Moon differs from most satellites of other planets in that ...
user5434678's user avatar
0 votes
1 answer
400 views

What model best describes the alignment of the Sun and Moon during a lunar eclipse?

In the first image the penumbra shadow area is rather small and would match the time length of a lunar eclipse, However, the light source/Sun is far too distant to match the Sun in scale to the Earth ...
user5434678's user avatar
2 votes
2 answers
566 views

Old moon in the new moon's arm

I understand the phenomenon I want to explain is something known as Earth Shine. What is Earthshine and what causes Earthshine? Is it really normal? What exactly is the less illuminated part in the ...
Vini's user avatar
  • 175
4 votes
1 answer
1k views

How often does the moon "set" for us compared to the sun?

I am working on a game, and I have a day/night cycle. Currently I have the sun. Currently every "sun day" is 24 hours, with that being said, how long is every "moon day"? In other words, how much does ...
Jayden Miller's user avatar
8 votes
1 answer
722 views

What would happen if we removed Earth's moon?

This question is an object of fascination of mine. There are a few different angles to take to it. My favorite is blasting the moon out of existence while its moving away from Earth. What would ...
ethug's user avatar
  • 89
12 votes
3 answers
848 views

Does the gravitational pull of the moon affect the composition of Earth's atmosphere?

In particular, does the pull of the moon affect the amount of water vapour in the Earth's atmosphere? In other words, if the moon were larger, or orbiting more closely to the earth, would the ...
LulalaBoss's user avatar
22 votes
2 answers
965 views

Is there geological evidence that the moon once collided with the Earth?

I've seen models in astronomy that show how the Earth-Moon system must have come together after a collision. However, I have not heard whether there is any actual physical evidence on Earth that ...
f.thorpe's user avatar
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6 votes
1 answer
293 views

Why does helium-3 stay in the moon and not escape from it?

So the moon is full of helium-3. Since it's a gas in the moon's vacuum... Why doesn't it escape?
InquilineKea's user avatar
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10 votes
2 answers
147 views

Who originated Taylor's axiom of lunar formation, and where?

I've been doing a bit of reading about the formation of the moon, and I've found multiple references (1, 2, 3) to something called Taylor's axiom, stated in link (3) above as: The best models for ...
senshin's user avatar
  • 1,885
12 votes
1 answer
739 views

What causes "shallow" moonquakes?

It is thought that "deep" moonquakes are caused by tidal forces exerted on the Moon by the Earth and Sun. Some other sorts of moonquakes are thought to be caused by impacts, or by thermal expansion (...
senshin's user avatar
  • 1,885
4 votes
1 answer
243 views

What is the furthest observable phenomenon from Earth that is Earth Science?

Guessing that the Earth's magnetic field is the furthest observable Earth Science related phenomenon from Earth itself, though not completely sure.
blunders's user avatar
  • 4,601
20 votes
1 answer
298 views

What can we learn by studying lunar atmospheric tides?

Lunar atmospheric tides are likely insignificant for weather, although Guoqing (2005) asserts that The lunar revolution around the earth strongly influences the atmospheric circulation. They don't ...
gerrit's user avatar
  • 11.7k
15 votes
2 answers
557 views

Why is there a daily inequality for low tides?

I understand why there is a daily inequality for high tides. What I do not understand is why the low tides are not equal. The data all seems to be somewhere along the lines of but the theory seems to ...
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