Have you ever wondered why we can't see the other side of the moon?

In summary, the conversation discusses the concept of the moon's rotation and its relation to the phases we see. It is explained that the moon's rotation and its phase are not related, and the moon rotates once on its axis per orbit of the Earth. The idea of synchronous rotation is also mentioned, where the moon's rotation does not depend on the side we see. It is suggested to simulate this concept with objects and a rotating chair, and to consider the moon's rotation from different perspectives.
  • #1
akashpandey
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We all know we see only one part of moon means part which is facing towards earth
But moon rotates also so we should able to see its other part(dark part) but we cant.
I know rotational period of moon is equal to revolutionary period of moon but if moon is having rotational motion
So we should able to see other part
 
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  • #2
You should try to simulate this using objects sitting on the table in front of you.
 
  • #3
Ya i did but rotation without changing the phase is possible? How and why?
 
  • #4
"Dark Part" ? - The times I read this "Dark Side" nonsense - The Moon experiences day and night just like the Earth.
 
  • #5
akashpandey said:
Ya i did but rotation without changing the phase is possible? How and why?

I'm sorry, I'm having a little trouble understanding your post. Can you elaborate a little on what you did?
 
  • #6
akashpandey said:
Ya i did but rotation without changing the phase is possible? How and why?
The rotation of the moon and its phase are totally unrelated. The moon could rotate at any rate and the phases would look exactly the same in terms of what fraction of the moon is illuminated at what time. Also, from the OP:
...we should able to see its other part(dark part) but we cant.
Sure we can: the "dark part" is the part that isn't illuminated when we look at the moon on any day it isn't full.

If instead you mean the far side of the moon, which is totally different from "dark part", again, look at the objects sitting on the table in front of you. It should be easy to see how you can have the moon rotate once per revolution and therefore always have the same part facing the Earth.
 
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  • #7
and7barton said:
"Dark Part" ? - The times I read this "Dark Side" nonsense - The Moon experiences day and night just like the Earth.
Right. The "dark part" changes once per [lunar] day just like on Earth. There is no "dark part" or rather, no part that is always dark (aka: dark side of the moon).
 
  • #8
akashpandey said:
Ya i did but rotation without changing the phase is possible? How and why?

maybe not done quite right, as Russ said, the phases are unrelated to rotation on its axis
The moon rotates once on its access per 1 orbit of the earth, this is called Synchronous Rotation

have a look at this animation



you can see from looking down on the moon and Earth from above that the moon does indeed rotate once on it's axis per orbit of the Earth they do a couple of other examples of non-axial rotation and multiple axial rotations first

you can simulate this at home using a couple of balls one for Earth and one for the moon. put a mark on the face, facing earth, of the moon ball and observe from aboveDave
 
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  • #9
So phase(side) of moon and rotation is not related,ok done.
Means synchronous rotation is exception case of rotation in which rotation does not depend on side we see am i right?
 
  • #10
akashpandey said:
Means synchronous rotation is exception case of rotation in which rotation does not depend on side we see am i right?

Exception to what? All movement is relative.

Consider a merry-go-round. If you walk around one at the same speed as it rotates you will always see the same side. The merry-go-round appears stationary to you but it is still rotating with respect to the earth.

Viewed from the Earth the moon always shows the same side (it appears stationary/not rotating), however viewed from the sun the moon can be seen rotating and there is no permanently dark side.
 
  • #11
Get yourself a rotating office chair. There are so many Astronomy Simulations you can do with it. If you also happen to have a football or tennis ball, you can really enjoy yourself. I remember getting a girl in a Science class to do pirouettes around the classroom to show the difference between Solar days and sidereal days. She enjoyed being the centre of attention and the (low ability) class were entertained and possibly enlightened a bit. RESULT!
 

1. What is the difference between spin and rotation of the moon?

The terms spin and rotation are often used interchangeably, but there is a subtle difference between the two. Spin refers to the motion of an object around its own axis, while rotation refers to the motion of an object around another object. In the case of the moon, its spin and rotation are synchronized, meaning that it takes the same amount of time for the moon to complete one full rotation on its axis as it does to orbit around the Earth.

2. How long does it take for the moon to complete one full rotation?

The moon takes approximately 27.3 days to complete one full rotation on its axis. This is the same amount of time it takes for the moon to complete one orbit around the Earth, which is why we always see the same side of the moon facing us.

3. Does the moon always rotate at the same speed?

Yes, the moon rotates at a constant speed. This is due to the tidal forces exerted by the Earth, which have caused the moon's rotation to become tidally locked. This means that the moon's rotation and orbit are synchronized, causing it to always rotate at the same speed.

4. How does the spin of the moon affect its surface?

The moon's spin plays a crucial role in shaping its surface. The moon's spin creates gravitational forces that cause its surface to bulge slightly, resulting in tidal forces that create features such as mountains, valleys, and craters. The spin also affects the distribution of heat on the moon's surface, which can impact the formation of geological features.

5. Is the moon the only celestial object with synchronized spin and rotation?

No, the moon is not the only celestial object with synchronized spin and rotation. Many moons in our solar system, such as Jupiter's moon Io and Saturn's moon Titan, also have this characteristic. In addition, some planets, such as Mercury, have a spin and rotation that are synchronized to different degrees, resulting in a phenomenon known as a "spin-orbit resonance."

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