Terry Starling,  Texas for his question:

What is the Solar System?

A system is a group of objects that work together as a unit. A telephone system includes lines, switchboards, dial phones and countless other connected parts. The Solar System is a group of related heavenly bodies. All are connected with each other.

The giant sun is the center of the system. Its mighty gravitation holds the smaller planets, moons and comets in their places They travel in orbits around the sun. This gives them centrifugal force ‑ the same force which keeps water in a pail when you swing it around fast.

The sun's gravitation keeps the smaller bodies from leaving the Solar System. Centrifugal force prevents them from falling into the sun. This perfect balance keeps the Solar System in order,

There are nine known planets, numerous moons, almost 100 comets and countless asteroids in our Solar System. Mercury is only 36 million miles from the sun. The planet Pluto is about 3,670 million miles from the sun. The other planets are spaced at intervals between these, the inner and outer planets. It was proved long ago that our Solar family is very well run. There is no chance of a planet getting out of line and bumping  to another planet,