1) A space
2) Gravity is the “curvature” of space. The larger the mass, the greater the “curvature” of space and, therefore, lighter objects “roll” into this “curvature”. All objects that revolve around the Sun are held in their orbits by gravity
3)People want to know about the existence of other planets, the inhabitants of these planets. They also would like to know about the limit of the cosmos and whether it exists at all.
