We know that the first man to walk on moon was Neil Armstrong. it is said that there is no force of gravity on moon. then how did Neil Armstrong moved a few steps on moon?
Who says there is no gravity in moon?
The acceleration due to gravity on moon is 1/6 that on earth.
I feel that you are confused by the concept of weightlessness in satellites.
On moon, it has its own gravity which is one sixth that on earth.