The solar system consists of the Sun; the nine planets, about 90 satellites of the planets, a large number of small bodies (the comets and asteroids), and the interplanetary medium. (There are also many more planetary satellites that have been discovered but not yet been officially named.) The inner solar system contains the Sun, Mercury, Venus, Earth, and Mars.
Diagram of Solar System (Inner)
The above diagram shows the relative sizes of the orbits of the inner planets from a perspective somewhat above the ecliptic (hence their non-circular appearance). The planets of the outer
solar system are Jupiter, Saturn, Uranus, Neptune and Pluto. Diagram of Solar System (Outer)
The orbits of the outer planets are shown above. The orbits of the planets are ellipses with the Sun at one focus, though all except Mercury and Pluto are very nearly circular. 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 planeof the Sun’s equator. Pluto’s orbit deviates the most from the plane of the ecliptic with an inclination of 17 degrees. They all orbit in the same direction (counter-clockwise looking down from above the Sun’s north pole); all but Venus, Uranus and Pluto also rotate in that same sense.