Understanding Moon's Lack of Gravity: The Science Behind It

In summary: The density of the moon is less than that of Earth. This is why the moon's gravitational field is weaker than Earth's.
  • #1
jtesttubes
16
0
What are the properties constitute to have zero gravity in moon. Why Earth has gravitational force while moon does not have? I need a concrete scientific explanation.
 
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  • #2
The moon does have gravity. Notice the pics of the Apollo astronauts walking about. Haven't you seen the video of the dropped hammer and feather experiment?
 
  • #3
jtesttubes said:
What are the properties constitute to have zero gravity in moon. Why Earth has gravitational force while moon does not have? I need a concrete scientific explanation.

The moon does exert a force on other objects that have mass. In the parlance of our times, it does have gravity. Now the moon does not have an atmosphere... is that what you meant?
 
  • #4
http://nssdc.gsfc.nasa.gov/planetary/lunar/apollo_15_feather_drop.html"
 
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  • #5
jtesttubes said:
What are the properties constitute to have zero gravity in moon. Why Earth has gravitational force while moon does not have? I need a concrete scientific explanation.
The moon's gravitational force is weaker than the Earth's because gravitational force is directly proportional to mass, and the moon's mass is smaller than the earth's.
 
  • #6
Don't forget that g actually depends on distance from the centre of the planet (radius) and the density.
 
  • #7
anything with mass has gravity
 
  • #8
sophiecentaur said:
Don't forget that g actually depends on distance from the centre of the planet (radius) and the density.

density?
 
  • #9
Well, it depends on the mass and that is the product of volume (which depends on radius) and the density.
 
  • #10
Anonymous217 said:
density?
Yes, density determines where the surface of the mass is and the resultant gravity. If we create a new planet with higher density than the Earth with the same mass but with the size of the Moon, this object would have higher gravitational pull on its surface than both the current Moon and Earth. Because you're close to the centre.
 
  • #11
This is one of the many examples in Science where the actual FORMULA says it all and much better than words.
 
  • #12
jtesttubes said:
What are the properties constitute to have zero gravity in moon. Why Earth has gravitational force while moon does not have? I need a concrete scientific explanation.

You have been wildly misinformed sir. The moon has gravity, about 1/6 the gravity that Earth has. Any thing with mass (everything really) has gravity. Even light has it's own gravity (since light is a form of energy and the mass off energy is equal to energy/the speed of light^2).
 
  • #13
the moon does have gravity however its gravitational potential energy is much less than that on earth, due to the mass difference, since the moon has less mass than Earth its gravitational pull is much weaker. Earth's GPE is roughly 9.8 Moons GPE is i think around 1.6~1.8
 
  • #14
doc.madani said:
the moon does have gravity however its gravitational potential energy is much less than that on earth, due to the mass difference, since the moon has less mass than Earth its gravitational pull is much weaker. Earth's GPE is roughly 9.8 Moons GPE is i think around 1.6~1.8
Don't confuse gravitational potential energy with the strength of the gravitational field at the surface. The strength of the Earth's gravitational field is about 9.8 N/kg (or m/s^2) at its surface, while the moon's is about 1.6 N/kg at its surface.
 
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  • #15
Potential is -GM/r.
Field (g) is GM/r2.

M= 4pi r3 d/3
(where d is density)
So
g = 4pi G d r3/3r2
which means g = 4pi G d r/3
and the potential is -4pi G d r2/3

That says it all, doesn't it?
 

1. Why does the moon have no gravity?

The moon actually does have gravity, but it is much less than the gravity on Earth. This is because the moon has significantly less mass than Earth, so its gravitational force is weaker.

2. How does the lack of gravity on the moon affect objects and people?

The lack of gravity on the moon means that objects and people will weigh much less than they do on Earth. This can make movement and activities such as walking and jumping easier. However, it can also cause problems with balance and coordination.

3. Why can astronauts jump higher on the moon?

Astronauts can jump higher on the moon because there is less gravity pulling them down, so they are able to propel themselves higher with less effort. This is similar to how jumping on a trampoline allows you to jump higher due to the rebounding force of the surface.

4. Does the moon's lack of gravity affect its orbit around Earth?

Yes, the moon's lack of gravity does affect its orbit around Earth. The moon's orbit is determined by the balance between its speed and the gravitational pull of Earth. With less gravity, the moon moves faster and has a slightly different orbit than it would if Earth's gravity was stronger.

5. How does the moon's lack of gravity impact the tides on Earth?

The moon's lack of gravity does not have a direct impact on the tides on Earth. Tides are caused by the gravitational pull of the moon and the sun on Earth's oceans. However, the moon's weaker gravity does contribute to the overall gravitational forces that create tides.

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