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Mars has the tallest mountain in the solar system—and the
deepest canyon. It also has the fiercest twisters. No wonder Mars
has fascinated people for centuries.
Mars is about half the size of Earth. Deep channels
crisscross the planet’s rusty-red surface. Scientists think the
channels may have carried water long, long ago.
Like Mercury, Mars has almost no atmosphere. But guess
what Mars does have—two small moons. Phobos and Deimos
orbit very close to their parent planet.
A day on Mars is about twenty-four hours long. But the red
planet takes almost twice as long as Earth to orbit the Sun. Its
year lasts 688 Earth days.
Mysterious Mars
