Without the light and heat of the Sun no life would now be, or in
the past have been, possible on this Earth, or any other planet of
the solar system.

The eight planets of the solar system are divided into four inferior
and four superior.

The inferior planets are Mercury, Venus, the Earth, and Mars. The
superior are Jupiter, Saturn, Uranus, and Neptune.

The diameters of the smaller planets are as follow: Mercury, 3,008
miles; Mars, 5,000 miles; Venus, 7,480 miles; the Earth, 7,926 miles.

The diameters of the large planets are: Jupiter, 88,439 miles; Saturn,
75,036 miles; Neptune, 37,205 miles; Uranus, 30,875 miles.

The volume of Jupiter is 1,389 times, of Saturn 848 times, of Neptune
103 times, and of Uranus 59 times the volume of the Earth.

The mean distances from the Sun are: Mercury, 36 million miles; Venus,
67 million miles; the Earth, 93 million miles; Mars, 141 million miles;
Jupiter, 483 million miles; Saturn, 886 million miles; Uranus, 1,782
million miles; Neptune, 2,792 million miles.

To give an idea of the meaning of these distances, I may say that a
train travelling night and day at 60 miles an hour would take quite
176 years to come from the Sun to the Earth.

The same train, at the same speed, would be 5,280 years in travelling
from the Sun to Neptune.