Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [moon]

For questions that relate to Earth's natural satellite.

8
votes
1answer
60 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 ...
2
votes
0answers
89 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 ...
6
votes
5answers
149 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...?
2
votes
1answer
34 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 ...
9
votes
1answer
228 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....
22
votes
1answer
12k 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 ...
1
vote
2answers
725 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?
-4
votes
1answer
69 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?
4
votes
1answer
371 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 ...
2
votes
3answers
325 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?
6
votes
1answer
1k 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?
4
votes
1answer
1k 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 ...
2
votes
0answers
40 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 ...
5
votes
1answer
77 views

What is the characteristical 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 ...
8
votes
1answer
91 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 ...
3
votes
1answer
905 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 ...
4
votes
2answers
2k 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 ...
2
votes
2answers
554 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 ...
0
votes
1answer
139 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 ...
2
votes
2answers
213 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 ...
4
votes
1answer
557 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 ...
8
votes
1answer
500 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 ...
12
votes
3answers
518 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 ...
20
votes
1answer
398 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 ...
5
votes
1answer
155 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?
7
votes
1answer
96 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 ...
12
votes
1answer
485 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 (...
4
votes
1answer
224 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.
20
votes
1answer
228 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 ...
14
votes
2answers
375 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 ...