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Anyone who has peeked over
the rim of the Grand Canyon comes away awed, because there is nothing like it
on Earth. Martians, however, would merely chuckle.
Mars has Valles Marineris,
a system of canyons that stretch for 2,485 miles (4,000 kilometers -- almost
the entire width of the United States.
Side canyons are often up
to 60 miles (100 kilometers) wide. The central gorge is 370 miles (600 kilometers)
across in places. At some spots along the rim, you'd have to look 6 miles (10
kilometers) down to find the bottom. That's six or seven times deeper than the
supposedly Grand Canyon.
This image was created by
the U.S. Geological Survey by merging Viking mission images with topographic
data. It shows just a portion of Valles Marineris. The location, Candor Chasma,
is one some scientists suspect has been sculpted at least in part by flowing
water.
-- Robert
Roy Britt
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