1. THE SOLAR SYSTEM

With respect to the photo showing the planets with their sizes on scale, note that the distances are not on scale! The planets Venus, Mercury, Earth and Mars are called "the small planets" or "the planets of the inner solar system", the "large planets" of the" outer solar system" are Jupiter, Saturn, Uranus and Neptune. Pluto is no longer called a "planet" but a "dwarf planet" and perhaps not a real planet at all.
You see in the picture that there are more "dwarf planets".