Earths' Gravity/Atmosphere?

Question

Does Earth's gravity gradually become less and less as you go higher, or is there a point in which gravity ceases, in which case where is this point?
And, where does space start? The point where there is no atmosphere, or no gravity, or the first point with neither?

Answer 1

Theoretically, no matter how far away you go from an object, you wil always be in a gravitational field. This can be seen by the equation

g = (GM)/r^2

where g is "acceleration" of gravity, G is the gravitational constant, M is the mass of the object causing the field, and r is the distance from the center of mass of that object.

To see how this works, you can just use g = 1/r^2 and keep making the distance, r larger and larger using a calculator. You will see that the answer you get, g, never reaches zero (though your calculator may eventually approximate it to zero).

So we say, as you move away from the object, the acceleration of gravity APPROACHES zero, but it can't actually reach it.


However there are areas in space where the net gravitaiton force on a object can be zero.

Answer 2

It really depends how far into the physics you actually want to go. According to physics equations the gravitational field around a planet, earth or otherwise, never ceases. You could be over 100,000 miles away and still be affected by its gravity, though the force would be so small it is unnoticable. For example, though Jupiter is so far away, its gravitational field stretches as far as the earth. The force exerted on earth makes no difference as the it is so small.
As for the atmosphere, it gradually disapears, hence the higher you are, the less dense the air is and the less oxygen there is, though i believe there is a definite line where the atmosphere ends.
Hope i've helped.

Answer 3

Gravity obeys an inverse square law. That means that if you get twice as far away, gravity is only 1/4 as strong; 10 times as far away gravity is 1/100 as strong, and so on. It never goes to zero.

The atmosphere does not really have a sharp cutoff either. Atmospheric density falls off exponentially, which is much faster than the inverse square rate at which gravity falls off, so that higher than a few hundred miles it is practically zero. At some point above that the solar wind is denser than the Earth's outer atmosphere and that could be called the end.

Answer 4

At the top of Mount Everest, you actually weigh slightly less than you do at sea level. The same goes for when you are at 30,000 feet in a passenger jet.
You weigh less and less the further distance you are from the Earth, the Moon, Mars or even an asteroid.

Space and atmosphere gradually blend together pretty much in line with the ammount of gravity present.

Answer 5

The gravitational strength varies inversely with the square of the distance from the centre of the earth. And if you plot a graph of gravitational strengh (y-axis) against distance (x-axis), the curve approaches the x-axis (in an inverse correlation) but NEVER touches it (x-axis is an aymptote of the curve). Wherever you are in the universe, you will still be affected by earth's gravity but it will be too negligible to cause a pull.
The higher you are from earth, the thinner the atmosphere. Until the atmosphere disappears, space begins. Simple as that.

Answer 6

Gravity decreases with the inverse square of distance, so basically, the gravitational effects of Earth are felt in the Andromeda galaxy.

Between the Earth and the Moon, there are 'Lagrange' points, where the gravitational effects of the two bodies cancel each other out.

Space starts where the atmosphere ends.

Answer 7

Earth's gravity does become less as the distance from the center increases....but never reaches zero...all objects in the universe attract each other. There is gravity between you and I. Space start where we say it does...usual definition is where we can see the curvature of the earth.

Answer 8

no earth's gravity does not cease. space starts where there is no atmosphere, or where there is a miniscule amount of gas in the atmosphere.

Answer 9

There is no gravity on a object if it is far enough from the other object, this distance is determined by the mass of the objects, and i hear space has no begginning and no end.

Answer 10

you will be subjected to lessened gravitational force as your move farther from the earth's center of mass.

keep in mind we are already ~4000 miles from the center of mass. So the extra 60-100 miles to "weightlessness" is ~2% difference. Not much in the grand scheme of things.