David Russell, age 10, of Indianapolis, Indiana for his question:

Is the earth part of the Milky Way?

Our great big globe is just a tiny planet of the Solar System. The Solar System is just one tiny family of heavenly bodies in the vast Milky Way System of stars. The Milky Way, also called the Galaxy, is a huge cartwheel system of stars, measuring about 100,000 light years from side to side   and a light year measures almost six million, million miles.

The astronomers estimate that there are about one hundred billion stars in the great Milky Way and our sun is one of these teeming stars.

It is about two thirds of the way from the center of the Big Wheel. The Sun’s children include nine planets with their moons, a number of comets, many asteroids and countless meteors. All these heavenly children revolve around Father Sol. The sun and all the other stars wheel around with the Milky Way.