The canyons of Mars have captured the imagination of modern man for nearly four decades and continue inspire awe amongst the newest generation of sky watchers. From the earliest NASA Mariner flybys of Mars to the latest observations and explorations of the planet, it is clear that these canyons will continue to be full of surprises. As we continue to learn more about these remarkable Martian features, let’s take a look at how our views of the canyons of Mars have changed over the years.
Valles Marineris: The Grand Canyon of Mars
While Mars is home to many massive canyons, the Valles Marineris dwarfs them all, as well as all other known canyons in the solar system. The Valles Marineris stretches an astounding 2486 miles in length and dives as deep as 5 miles into the crust of Mars in some regions. To put the sheer size of the Valles Marineris in proper perspective, the canyon could easily extend through the diameter of Europe and is more than five times the size of Grand Canyon. The Valles Marineris is located near the equator of the planet and runs from the Noctis Labrithius to the Chryse regions of the canyons. The Valles Marineris was discovered in 1972 by the Mariner 9 Mars orbiter that the canyon is named after.
Discovery of the Canyons of Mars
Although Galileo was the first scientist to have observed the planet of Mars through a telescope in 1609, the process of identifying the key features took centuries, and it was not until the flyby of the Mars Mariner orbiters that astronomers finally got a clear view of the canyons of Mars. The discovery of the barren surface of Mars was in stark contrast to the signs of life or civilization that many respected thinkers had hoped would be found on the planet. However, the volcanoes and canyons of Mars like the Valles Marineris and the Ma’adim Vallis canyons opened a series of new areas to explore and new questions to answer.
Origins of the Canyons of Mars
In the years since the canyons of Mars were first discovered by the Mariner 9, a handful of different explanations have been put forth to explain their origin. Many layman and astronomers alike have been tempted to suggest that the canyons were created by great rivers or other bodies of water that once covered the surface of the planet. However, the generally accepted theory in the scientific community is that the largest canyons of Mars were created by shifts in tectonic plates long ago. While plate tectonics on Earth are still quite active, the inner core of Mars has been dormant for an indeterminate period of time. Nevertheless, it appears that the massive Valles Marineris canyon was created by a great tectonic shift in ancient Martian history that left the massive canyon in its wake.
Another theory of how the canyon was formed is that a very large asteroid collided with Mars some 400 billion years ago causing a rift in the crust of the planet. However, many astronomers and scientists hold out hope that the Ma’adim Vallis canyon may have once hosted a huge quantity of water due to the presence of sapping channels that are the result of erosion caused by groundwater.