
Newton came up with a set of equations that described gravity as a force. This was explained by imagining that a large object such as a planet emanated this force by sheer mass and spin, and then pull smaller objects, such as moons towards it.
It was shown by Isaac Newton that if an object is propelled forward in "empty" space it will keep going till it meets a similar or greater force or "drawn "by a planet and" fall" into a gravitational orbit.

Space is known to "curve" in the presence of matter. Black holes are thought to be the engines at the heart of galaxies which curve space so much that local solar systems feel the pulled in along the path of warped space-time creating a system orbit.
A system of axes that form a frame of reference. The three dimensions of space and the dimension of time can be taken to form a four dimensional continuum: this was suggested by Minkowski in connection with special relativity. Source Oxford Mini Dictionary of Physics.



That stuff between these words and your eyes, the medium between our Earth and Moon. How is it possible to grasp on something that "cant be seen, felt or measured" This strange medium when combined with Time holds our Solar System in "place", drawn to the centre of the Milky Way (our Galaxy) in much the same way as our "home" is drawn to the Sun.
Acceleration due to gravity