Comparing gravity on earth to gravity in space
1) Gravity, as defined by science, is a force of attraction between objects in space that depends on How big the objects are and how close they are to one another.
2) The force of gravity between objects in space is felt at any distance. It just gets weaker and weaker as the objects get farther and farther apart. Stars are light years apart (the distance that light travels in 1 year i.e. 5,865,696,000,000 miles '186,000 miles * 60 sec * 60 min * 24 hrs * 365 days') and yet they pull on one another all the time. It takes thousands and millions of years to see any change, but it slowly pulls stars and planets closer and closer together. This weak gravity is what causes a comet to come closer and closer to the Earth as it travels around the Sun and causes it to swing back out into space as it whips around the Sun.
3) The force of gravity is a weak force. Most forces, such as electrostatic attraction (two pieces of paper clinging after being rubbed against you hair) are stronger than gravity.
4) You might ask, "Then why is gravity so strong on the Earth?" The answer is: Gravity on Earth is so strong because the Earth is soooooooooo BIG! Truly Big! The Earth is so big that if you were flying in an airplane at 100 miles per hour it would take you over 10 days to fly around it just once. The Earth is so heavy that if you dropped the empire state building on it, it would not even shake! So if you are standing on the Earth, it's gravity attraction is very strong. You can measure it by stepping on bathroom scales. The scale shows how much the Earth's gravity is pulling you towards it's center. You will notice that bigger things weigh more which proves that the gravity attraction is affected by the size and mass of both objects. I.E. your body and the earth.
But, if you are standing way out in space (you better have a space suit on) away from any planets or moons or stars then the force of gravity trying to pull you away from where you are is very small indeed. It is so small, even from our star (the Sun) you would probably not notice it moving you in a whole lifetime. In space the bathroom scales would say you are weightless. 0 pounds!
If you are standing in space and have a very big cast iron ball tied to a long string, weak gravity forces from distant stars will try to pull it out of your hands. You are so strong, compared to these gravity forces, that you would not even notice it. But if you wait around long enough, you will eventually notice that you and the ball are slowly moving towards the Biggest or the Closest star out there.
So, to sum up: Gravity in space is just like gravity on earth except being in space implies being away from any big objects, such as the Earth, and so the gravity forces pulling on objects in space are much smaller than on the Earth's surface.