Mercury was named after a
Roman god, the fleet-footed messenger, because it seemed to
move more quickly than any other planet. It is the second
smallest planet and the closest to the sun. It has a
diameter that is 40 percent smaller than the Earth's, and 40
percent larger than the Moon's. Also, it is even smaller
than Jupiter's moon Ganymede and Saturn's moon
Titan. If an explorer were to
step onto the surface of Mercury, he would find a world like
the moon. The dusty hills of Mercury were created by
meteorites hitting its surface. Mercury's surface looks like
one big chocolate chip cookie with craters dotting the
surface. An explorer would notice that the Sun appears two
and a half times larger from Mercury than it does from
Earth. In Mercury, the sky is always black because it has
almost no atmosphere to cause light to scatter. If you ever
go to space, you might see two bright stars. One of them
being a cream colored Venus and the other being a blue
colored Earth. Before Mariner 10, there
was little known about Mercury because of the difficulty in
observing the planet from Earth telescopes. Mercury can only
be viewed during daylight hours or just before sunrise or
after sunset. It takes Mercury
approximately 59 days for it to make a complete rotation on
its axis. Mercury rotates one and a half times during each
orbit.
