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

learn more… | top users | synonyms

27
votes
8answers
39k views

Why doesn't the Moon fall upon Earth?

Why doesn't the Moon, or for that matter anything rotating another larger body, ever fall into the larger body?
16
votes
3answers
62k 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 ...
9
votes
2answers
491 views

Why don't we see solar and lunar eclipses often?

Since we see the new moon at least once in a month when the Moon gets in between of the Sun and the Earth during the evening ( and as far as I know if this happens during the day, you'll get to see a ...
26
votes
4answers
5k views

Why is a new moon not the same as a solar eclipse?

Forgive the elementary nature of this question: Because a new moon occurs when the moon is positioned between the earth and sun, doesn't this also mean that somewhere on the Earth, a solar eclipse ...
15
votes
1answer
1k views

When will the Moon reach escape velocity?

From what I know, the Moon is accelerating away from the Earth. Do we know when it will reach escape velocity? How do we calculate this?
14
votes
5answers
5k views

Why do we always see the same side of the Moon? [duplicate]

I am puzzled why we always see the same side of the Moon even though it is rotating around its own axis apart from revolving around the earth. Shouldn't this only be possible if the Moon is not ...
9
votes
1answer
393 views

What causes a ring-like image around light of the moon?

I just encountered an interesting image in sky. As you can see in following images there was a ring-like image around light of the moon. I don't know if it was clouds but it was looking like it is far ...
5
votes
3answers
615 views

Why does the moon appear bigger close to the horizon, rising or setting? [duplicate]

Possible Duplicate: Why does the moon sometimes appear giant and a orange red color near the horizon? I made a little research about this and found this article ...
1
vote
1answer
1k 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 ...
1
vote
4answers
7k views

How does the moon reflect light?

We can see the moon in the night because it reflects sunlight. But the light is incident on the opposite side of moon with respect to the observer in the night. In this case, how does the moon ...
5
votes
1answer
351 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 ...
10
votes
1answer
482 views

Mars just collided with Earth! A question of eccentricity

One of the standard theories behind the formation of our Moon is the giant impact hypothesis, according to which Earth was struck by a Mars-sized body (about $10\%$ the mass of Earth) early in its ...
10
votes
1answer
384 views

How to explain the Moon halo phenomenon?

Today, here in Brazil, I have observed (and is still observing) an interesting phenomenon. The Moon is near to a big star in the sky, but this is normal. The interesting part is what's around them. ...
8
votes
1answer
347 views

Could the earth have another moon?

First, to clarify: I'm not asking if perhaps there's a moon that we haven't found yet. The question is, theoretically, would the earth be able to have another stable moon in addition to the current ...
6
votes
4answers
2k 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 ...
6
votes
1answer
602 views

Is there a simple yet accurate formula for where on Earth the Sun and Moon are directly overhead?

I'm trying to improve a site that shows the region of the Earth currently under daylight, and I need a formula that, given the current time, tells where (latitude/longitude) the sun and moon are ...
4
votes
2answers
781 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 ...
3
votes
1answer
98 views

How do the “tidal forces warming moons” theories hold when apart from heating from expansion, there may be also cooling from contraction?

I can understand a temporary heating, from the tital forces exerted on the moon but wouldn't there be cooling as well eventually when particles "give in" to contraction? Wouldn't they eventually net a ...
3
votes
1answer
281 views

The Moon is slowly moving away from the earth. Does this mean that a total solar eclipse wasn't possible at some point in earth's history?

When the moon was closer to earth, was it still possible to witness a total solar eclipse millions of years ago? Or was the view-able space so small that it was impractical to even witness it?
2
votes
3answers
393 views

The theory of moon creation when a Mars size planet hit Earth

As we know the predominant theory where does the moon come from is that a Mars size planet hit the earth and took a chunk out of it which eventually materialized into moon. My question is that if a ...