A smaller body orbiting a larger, primary body, where the primary body is not a star.

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Why are Lunar Eclipse more common than Solar Eclipse?

Why are Lunar Eclipse more common than Solar Eclipse? Chapter from Light My thoughts; Eclipse can only occur at new moon and moon orbit is inclined at an angle of about 5 degrees to the earth's ...
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1answer
56 views

How does the Moon influence atmospheric pressure?

I have just read in the Telegraph an article entitled Moon overhead makes rainfall lighter, scientists conclude. In that article there is the following statement: When the moon is overhead, its ...
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1answer
48 views

Optimal time for satellite rocket launch considering moon gravity [on hold]

As per this The Gravitational Force of the Earth and Moon on Each Other Moon is pulling us with a force equal to 1/300,000th of our weight. I have read this Is the fuel burn for a satellite launch ...
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1answer
79 views

How much force would it take for you stop the Moon from crashing into the earth once it has started to fall?

In my previous question, I asked how much force it would take to destabilize the Moon's orbit enough for the moon to start falling into the Earth and collide. Assume this has already happened. Now, ...
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1answer
52 views

How much force would be required to destabilize The Moons orbit enough for it to crash into the Earth?

It is known that the moon slowly drifts away from the Earth. How much force would be required to destabilize it in the opposite direction enough for it to accelerate and crash into the Earth? What ...
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14 views

Tidal Bulge on Earth due to Line of Action [duplicate]

I am in an intro to Statics course, and we briefly went over why tidal bulges occurred due to vectors in the line of action between the earth and the moon. I am confused because I do not understand ...
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36 views

How deep would a moonbase have to be dug for radiation protection?

The atmosphere of the earth protects us from cosmic rays and other kinds of space radiation. On the moon there is little to no atmosphere so anyone on the surface of the moon is directly exposed to ...
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1k views

True or false: the Moon was touching the Earth 1.2 billion years ago

A creationist website makes this argument for the 6,000 year old earth. I'm embarrassed to say I don't know how to do the math to evaluate the claim myself. However, the time scales involved seems ...
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What happened to Apollo's Saturn-third-stage rockets?

I read recently the original Apollo 11 press release and it mentions that the Saturn V's third stage (used for Trans-Lunar Injection) was deployed into a solar orbit of some kind: (Source: Press ...
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2answers
869 views

How many hours will there be in a day 5,000,000,000 years from now?

It is known that the moon is moving away from Earth 2cm a year, and in doing so makes the days longer. I want to know how many hours will have one day, when our planet is near its end.
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55 views

Reconciling geosynchronous orbits and why the moon is moving away

First time on PSE, and forgive me if the question doesn't make sense. Everything I've read, and the explanations make perfect intuitive sense, for why the moon is moving away from the earth is ...
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2answers
1k views

How does the Moon stay in orbit? [duplicate]

How does the Moon stay in orbit? The Moon has not reached escape velocity from the Earth, then how does the Moon stays in orbit?
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3answers
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If there is no gravity on the moon why is the american flag waving?

If there is no gravity on the moon, how could this flag be flapping in the wind? (see link) http://www.stumbleupon.com/su/2wD6eg/hea-www.harvard.edu/~fine/images/desktops/Armstrong.jpg
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1answer
1k views

If the Moon had gravity as good as the Earth and a magnetic field could it have supported life?

If the Moon had gravity as good as Earth and a magnetic field could it have supported life? Because if the Moon had gravity, it could have retained water more than is present today on the surface. ...
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3answers
2k views

How can we see the moon while it's between the Earth and the Sun?

I know this sounds like (and probably is) a stupid question, but I can't figure it out. As far as I know, the crescent shape of the moon is when the moon is on the sunny side of the Earth, but that ...
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3answers
101k views

Why does the moon sometimes appear giant and a orange red color near the horizon?

I've read various ideas about why the moon looks larger on the horizon. The most reasonable one in my opinion is that it is due to how our brain calculates (perceives) distance, with objects high ...
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3answers
4k views

Why is moonlight less colourful than yellow light?

Just what the title states; and this isn't an original question: On full-moon, moonlight is almost as bright as mid-dawn; yet there is hardly any colour visible. This is not the case with sunlight. ...
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2answers
50 views

Could self-powered human flight be possible in a pressurized dome on the moon? [closed]

Given on the moon (or other place with 1/6th the gravity of the earth, though let's use the moon to keep this anchored in a real scenario) a "flying room" within which to fly, such as a large enough ...
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2answers
2k views

What kind of cooling mechanism could be used in outer space?

This question arises out of this question on Quora - Apollo 11: 1969 Moon Landing: Did Neil Armstrong really land on the moon? I'm convinced with most of the explanations provided in the first ...
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0answers
16 views

Weight difference on full moon and no moon day [duplicate]

Since Moon has an impact of gravity, would same piece of mass be heavier on a no moon day (since moon is at opposite side, thus pulling downwards) and lighter on full moon day (since the moon is at ...
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1answer
6k views

Why does the Moon or the Earth revolve anti-clockwise?

The question is very simple: Why does the Moon or the Earth or any another planet revolve anti-clockwise? And can any planet (or satellite) revolve clockwise? What is the physical law for this ...
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0answers
21 views

The moon affects the motion of the oceans, but can the motion of the oceans affect the moon? [duplicate]

Obviously the earth's oceans have mass and therefore they have an attractive force upon the moon. However, let's say that we were to cover most of earth with tidal power generators that extract some ...
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2answers
315 views

Which will collide first, the moon and Earth, or Sun and Earth?

As time progresses, which scenario will happen first? The moon colliding with Earth, or the Earth colliding with the Sun? I figure the Moon and Earth will happen first, based on proximity, but the sun ...
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1answer
31 views

Based on measurements of a moon's orbit with respect to the planet, what can one calculate?

Question: "We observe a very small moon orbiting a planet and measure the moon's min. and max. distances from the planet's center, and the moon's maximum orbital speed. Which of the following CANNOT ...
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3answers
5k views

How does the central peak in moon craters form?

The central peak in many of the moon's large craters are visible with a telescope and they seem a little odd to me. Can someone explain how they form.
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1answer
307 views

How does the Moon cause the tides?

I am considering the following question, but I can't quite figure it out... I have looked up differential gravity, but I cannot derive the equation for the effect on Earth, and I haven't found any ...
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1answer
80 views

What is the outward force on the Moon that makes it go in orbit rather that falling straight to the Earth? [duplicate]

So, we know that the gravity is responsible for pulling the Moon towards the Earth. But because it moves in an orbit, it makes me think that there must be a force that is causing the moon to travel in ...
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2answers
3k views

How is the Earth heated by a Full Moon?

While the moon is certainly not a good reflector of solar radiation, surely the radiation it reflects back heats the Earth (even if it is a terribly small amount). How would one go about calculating ...
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1answer
122 views

What will be destroyed? The Moon or the Death Star?

The situation: Suppose Death Star passes by the Earth towards the Moon (near speed of light) and fires its laser (starting from the center of Death Star) against the Moon. If the laser gets to the ...
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1answer
100 views

Why the moon doesn't fall down to earth? [duplicate]

Why the moon doesn’t fall down to the earth? We know that the moon travels in speed perpendicular to the gravity of the earth so that it doesn’t fall down to earth. But what if we supposed that the ...
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1answer
58 views

Why does Moon always poses the same face towards Earth?

If both Earth and Moon are rotating as well as revolving around some focus, shouldn't they have drifted out of phase with each other long ago? So, why do we always see the same side always?
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1answer
901 views

Can you tell just from its gravity whether the Moon is above or below you?

If you are on a place of Earth where the Moon is currently directly above or directly below you, you experience a slightly reduced gravitational acceleration because of Moon's gravity. This is what ...
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2answers
484 views

Why Does The Moon Apear White/Grayish and The Sun Yellow? [duplicate]

The Sun, as we all know, is white. Because our atmosphere scatters light the sun appears yellow to us hear on earth. So, why isn't the moon also yellow. Doesn't our atmosphere scatter its light. How ...
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1answer
58 views

Will climate change cause the Moon to move away from the Earth at a faster rate?

The Moon is moving away from the Earth at a rate of 38.08 ± 0.04 mm/year. This is caused by the tidal bulges being pushed ahead of the Moon as the Earth rotates and the landmasses interact with the ...
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5answers
6k views

Does the moon affect the Earth's climate?

So, this morning I was talking to a friend about astronomical observations, and he told me that lately there has only been good weather when there was a full moon in the sky, which was a shame. I ...
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0answers
48 views

Do I weigh less during high tide? [duplicate]

Given weight = mass * gravity do I weight less during high tide and more when tide recedes? My guess is weight = mass * gravity * gravitational pull of moon factor
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1answer
258 views

Why doesn't the moon crash into the Earth?

I was searching about 'why do not moon crash to earth due to its gravity?'Then by reading physics stake exchange existing questions I came to know that its the sideways motion of the moon that keeps ...
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1answer
115 views

Is it possible that Mercury collided with Earth, thus creating the Moon?

I recently heard a theory that Mercury might have been bigger before a massive collision that shrunk it and sent it on its current orbit. I also heard that a possible explanation for the formation of ...
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5answers
2k views

Why is the surface of the Moon white?

Why is the surface of the Moon white? Rather, what makes the surface white?
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5answers
2k views

Does the Moon's core still contain significant heat?

On earth, using earth-sheltering techniques can significantly reduce the temperature fluctuations on a structure. Would the same statement be true as well on the Moon? Does the Moon's core still ...
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2answers
367 views

Will Neil Armstrong's moon boot marks really last for thousands of years?

This question concerns the residual heat (if any) contained within the Earth's moon. At the time of the Apollo moon landings, it was widely reported that the boot marks left by the astronauts would ...
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5answers
5k views

Why is the sky of the moon always dark?

Why is the sky of the moon always dark compared to the sky of the earth, doesn't it have day and night like earth?
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2answers
705 views

Why is space black? [duplicate]

We on earth see the space black only at night. But on moon it observed that the space is black in both day and night even though the source is same for both ( the sun).Why? And also there are many ...
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2answers
71 views

Gravity underground on the moon?

They say that gravity Decreases as we dig into the earth. But I also read that gravity increases for the first approx. 2000km of distance underground. Using this rational, could we dig about 200 to ...
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1answer
2k views

Correlation between speed, distance, mass, etc between a planet and a star (or moon and planet)?

While playing around with some little scripts, generating solar systems, I started to wonder about the correlation between the different objects. Up until now, distance, mass, size and speed are ...
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0answers
45 views

Gravity between Moon and Earth [duplicate]

It's known that the greater the mass the stronger its gravitational force. Hence, Sun's gravity is definitely stronger than Earth's. So the question arises that why does the Moon orbit around the ...
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2answers
125 views

Is it possible to apply Newton's equation of gravitation to attractive force between the moon and the ocean? [closed]

Someone was asking me how much force is acting on the waves when the moon is closest to the earth. Of course the first thing I tried to do is apply Newton's equation for universal gravitation $$F = G ...
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2answers
303 views

Next crescent moon?

How do I find the date of next crescent moon on Wolframalpha or any other site which tells the appearance date time of next crescent on a specific location? I am searching for it to look for 1st of ...
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1answer
101 views

Is sunlight like a spotlight? [closed]

It is believed that if earth would have no atmosphere then the sunlight would fall on earth like a spot light. According to this fact the sunlight on moon must fall like a spot light. Does it? Then ...
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1answer
62 views

How bright would the Earth be at night without the moon?

How bright would the Earth be at night without the moon? Specifically, how much light would reach the surface of the Earth at sea level?