solar system consists of the Sun, the nine planets, sixty-three (63) satellites
of the planets, a large number of small bodies (the comets and asteroids), and
the interplanetary medium. The orbits of the planets are all more or less in the
same plane (called the ecliptic and defined by the plane of the Earth's orbit).
The ecliptic is inclined only 7 degrees from the plane of the Sun's
The whole solar system, together with the local stars
visible on a clear night, orbits the center of our home galaxy, a spiral
disk of 200 billion stars we call the Milky Way. Our solar system is
situated within the outer regions of this galaxy, well within the disk but
about 28,000 light years from the Galactic Center. Therefore, the Milky
Way shows up as a luminous band spanning all around the sky.