Solar system Computer artwork of the planets of the solar system seen from the surface of the Earths Moon upper right The planets are clockwise from upper left Saturn Uranus Earth Jupiter Mars and Neptune The orange planet at upper centre is Venus and the small brown planet at centre is Mercury The small blue planet at bottom left is Pluto Mercury Venus Earth and Mars the inner planets are dense and rocky Jupiter Saturn Uranus and Neptune are gas giants composed mainly of hydrogen and helium Pluto the smallest and most distant planet from the Sun is also thought to have a rocky core The Moon is the Earths only natural satellite