The Milky Way galaxy, in which the sun and planets reside, is a fairly typical spiral galaxy, flat and spinning around its center, with arms extending into space. It appears as a band of light from Earth, because we view it edge-on from inside. Galileo was the first to distinguish individual stars in the Milky Way. With billions of stars, the probability of discovering other planets around other “suns” is high. The astronomer Oort and his associates have proven the spiral configuration of the galaxy and have mapped its structure, center, arms, and many individual stars, especially those closest to the Sun.