THE UNIVERSE -- THE SOLAR SYSTEM -- PLANETS -- SUN -- MOON --
CONSTELLATIONS -- STARS -- COMETS -- METEORS -- NEBULÆ -- NEBULAR
HYPOTHESIS -- ECLIPSES -- MYTHOLOGY OF THE CONSTELLATIONS --
DICTIONARY OF SCIENTIFIC TERMS USED IN ASTRONOMY.
[Illustration: =HOW THE PLANETS WOULD APPEAR IF GROUPED IN SPACE=
In the above picture we have represented the planets of the Solar System
as we should see them from the earth if the human eye could grasp a
space of such immensity. The spectator is supposed to be standing on the
earth, and the moon is in the foreground, 240,000 miles away. The
planets are in their order outward from the sun, and vary in distance
from 40,000,000 miles, in the case of Mars, to 2,700,000,000 miles in
the case of Neptune. From the bottom upward, the planets are Mercury,
Venus, Mars, Jupiter, Saturn and its rings, Uranus and Neptune.]