What is Neptune's gravitational attraction?

Answer 1

Using "Newton Law of universal gravitation" it is calculated to 11.15 m/s2. Very close to earth (9.81 m/s2) despite it is 4 time bigger radius and 17 time more mass.

It is because gravity is proportional to mass but inverse proportion to square of the radius. Neptune density is less dense than earth thus comparatively low gravity to its' size.

Answer 2

It depends on the point in its atmosphere that you calculate it.

The strength of a planet's gravitational field depends on how far you are from the center of the planet. The Earth has a convenient reference-distance from the center, because it has a solid surface. The four 'gas giant' planets (Jupiter, Saturn, Uranus, and Neptune) have either no solid surface, or a very small one deep inside a tremendously dense atmosphere of gas and fluid. So before we can compare their gravity, we have to define how far from their center we're talking about.

A common diameter to talk about in reference to one of the gas giants is: the diameter where the atmospheric (gas) pressure is equal to the atmospheric pressure at sea level on Earth. For Neptune, this is beneath its opaque outer cloud layers.

The acceleration of gravity at that distance from the center is 11.0 m/s2.

Compared to earth, this is (11.0 / 9.8) = 1.122 times as large.

That means that for every 100 pounds you weigh on Earth, you would weigh about 112 pounds at that location on Neptune. The only way for this to occur would be within a structure (like a balloon) that was less dense than the atmosphere around it. Otherwise, it would be pulled down into the deeper regions.

Answer 3

7.92