slight force of gravity on an asteroid--An imaginary visit
to a world only twelve miles in diameter


CHAPTER VI

_JUPITER, THE GREATEST OF KNOWN WORLDS_ 160

Jupiter compared with our globe--His swift rotation on his
axis--Remarkable lack of density--The force of gravity on
Jupiter--Wonderful clouds--Strange phenomena of the great
belts--Brilliant display of colors--The great red spot
and the many theories it has given rise to--Curious facts
about the varying rates of rotation of the huge planet's
surface--The theory of a hidden world in Jupiter--When
Jupiter was a companion star to the sun--The miracle of
world-making before our eyes--Are Jupiter's satellites
habitable?--Magnificent spectacles in the Jovian system


CHAPTER VII

_SATURN, A PRODIGY AMONG PLANETS_ 185

The wonder of the great rings--Saturn's great distance and
long year--The least dense of all the planets--It would
float in water--What kind of a world is it?--Sir Humphry
Davy's imaginary inhabitants of Saturn--Facts about the
rings, which are a phenomenon unparalleled in the visible
universe--The surprising nature of the rings, as revealed