Of the nine Major Planets, Mercury, Venus,
the Earth and Mars are known as Inner Planets; Jupiter, Saturn,
Uranus, Neptune and Pluto as Outer Planets. The diameters of
the planets in thousands of miles are approximately Mercury
3, Mars 4, Pluto 4, Venus 71/2, the earth 8, Neptune 28, Uranus
31, Saturn 75, Jupiter 88. Owing to their greater distance from
the Earth, the big Outer Planets appear to be about the same
size as the others. Mercury and Venus are also known as Inferior
Planets. Others whose orbits are outside that of the Earth are
called Superior Planets.
The "Issued in" set has a well
known variation of this card.