Whyville's teleporters know all about Jupiter, yet another planet you can teleport
to here in our virtual town. But what is this place, other than a cool picture
and chat room?
Jupiter is the largest of all the planets, with a diameter more than eleven
times that of Earth. It has a greater mass than all the other planets combined.
Because it has such a huge mass, it also exerts a huge gravitational force on
everything around it. Some astronomers believe this force prevented the rocks
in the asteroid belt from forming a tenth planet.
Because of the gravitational forces on Jupiter, we would be compressed into
a puddle if we tried to walk around the planet! Its large size, plus the large
amount of light reflected by its clouds, makes Jupiter very bright in the night
Jupiter's most interesting features are its colored bands and the Great Red
Spot. The Great Red Spot is believed to be a hurricane, larger than the size
of two Earths. The storm is fed by constant high winds trigged by the enormous
planet's very fast rotation -- only 9 hours and 50 minutes. Compare that to
the much smaller Earth's 24-hour rotation! This hurricane existed hundreds of
years ago, back when people first looked at Jupiter through telescopes. It still
shows no sign of dying away.
Jupiter and its 16-or-so moons have been observed from close range by several
space probes. (Pioneers 10 and 11, Voyagers 1 and 2, and Galileo). You might
even be able to see four of these moons (Io, Europa, Ganymede and Callisto)
through binoculars. And if you have a good telescope, you can see Jupiter's
orbiting rings of rocks, a baby version of what Saturn has.
Although Jupiter is made of basically the same gases as the Sun, Jupiter is
not a star. The reason for this is because the pressure is not great enough
for the gases to have undergone nuclear fusion. The solar system was created
about 5 million years ago. If Jupiter had grown only ten times greater in mass,
then it would have formed another star, called a brown dwarf.
It's time for me to... BLAST OFF!