Why does Earth have gravity but space doesn ?
Space has LOTS of gravity! But I know you didn’t mean it that way. To explain: Gravity is rooted in matter which has “mass”. Mass acts on (affects) space in very specific ways (Einstein would say, mass “curves” space), and this action is transmitted by a force which Isaac Newton discovered and which we call gravitation. At least, this is what the theory of gravitation says, and from all our observations it seems to hold true. If it wouldn’t, our Apollo missions would not have reached the moon on their trajectories (and we would have been very surprised, I’m sure). On Earth, the gravity generated by its mass shows itself as a “pressure” on things physically connected to the ground, and we call that “weight”. When not connected, as for example in an orbit around Earth, there is no direct contact, thus no weight. But a spacecraft still has mass, and its mass generates its own gravity field (which is pretty close to nothing for small spacecraft, of course). Also, the gravitation going out
