Can a planet two, three, or even ten times the size of earth have the same gravity?
For example, I heard that a planet that is two or three times the size of earth but equal or close to the density earth has can have the same gravitational pull. Would that mean that if we were to find a planet with these characteristics would we be able to walk on its surface an experience little to no change in our weight?
For example, I heard that a planet that is two or three times the size of earth but equal or close to the density earth has can have the same gravitational pull. Would that mean that if we were to find a planet with these characteristics would we be able to walk on its surface an experience little to no change in our weight?
1 Answer
A planet with up to around twice the radius or eight the volume of the Earth could have the same gravity.
Explanation:
The gravity of a planet, or other body, is proportional to its mass.
The density of the Earth is about 5.51 g/
A planet with eight times the volume of the Earth would require a density of about 0.7 g/
Note that when referring to a planet being double the radius of Earth, it's volume goes up as the cube of the radius which is a factor of 8.
So a planet with up to twice the radius, or 8 times the volume, could have the same gravity as Earth.