The density of Earth is 5.52 g/cm3. The Moon’s relatively low density comes from the fact that it was mostly the Earth’s upper mantle and crust that was thrown up into space, and not very much of its core. The low density of the Moon means that it has less mass, and less gravity.

Not only is the Moon smaller than the Earth, but it is only about 60 percent as dense as Earth. Thus, the gravitational attraction on the Moon is much less than it is here on Earth, and a person weighs less on the Moon.

The force of the gravitational force of earth is more than the sun on moon.So the moon revolves around the earth not the sun.

Earth exerts a gravitational pull on the moon 80 times stronger than the moon’s pull on the Earth.

Jupiter

Near the surface of the Earth (sea level), gravity decreases with height such that linear extrapolation would give zero gravity at a height of one half of the Earth’s radius – (9.8 m.

The fact that objects move a lot in the universe and that the universe is expanding, can imply that gravity is a repulsive force that increases with distance.. so the farthest objects repel us more. The mutual repulsion of the particles may cause similar motion as if due to gravitational attraction.

Both in the Newton theory of gravitation and in the General Theory of Relativity the gravitational force is exclusively attractive one. However, the quantization of gravity shows that the gravitational forces can also be repulsive [3].

Albert Einstein’s special theory of relativity famously dictates that no known object can travel faster than the speed of light in vacuum, which is 299,792 km/s. This speed limit makes it unlikely that humans will ever be able to send spacecraft to explore beyond our local area of the Milky Way.