However, weight is a function of gravity. In space, it will be weightless. No, gravitional fields extend to indefinitely they do not suddenly stop once you get to a certain distance. It is referred to in everyday life as a unit of weight but this is not really correct.
Weight is the gravitional force exerted on a body but whatever planet etc.
In the SI system of units weight is measured in Newtons. When someone says that the weigh 70kg what they really mean is that the gravitional force exerted on them is equivalent to that exerted on a mass of 70kg.