Martian scene points to watery past

ESA / DLR / FU Berlin

New images of the northwestern rim of the Schiaparelli impact basin add to growing evidence of Mars’ watery past.

Evidence of Mars’ watery past is on full display in this new image of the Schiaparelli impact basin along the Martian equator. The entire basin is nearly 300 miles (460 kilometers) wide. The image from the High Resolution Stereo Camera on the European Space Agency’s Mars Express spacecraft zeros in on the northwestern rim, which cuts diagonally across this image from the top left to the bottom right. A 26-mile-wide (42-kilometer-wide) crater is embedded in the rim.

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ESA astronomers interpret the dark sediments on the floor of the Schiaparelli basin as evidence for water — resembling sediments that are deposited by evaporated lakes on Earth. The effect of other geological processes can be seen in the image, such as smaller craters created by the fallback of material that was ejected during the initial impact. Some of these were partially flooded and filled with watery deposits. Flows of lava appear to have created smooth plains.

The sediments forming the smooth plains in the lower left of the image have been modified by erosion — either by wind, or water, or both — to form sharp contours. In other places, material deposited by the wind forms hills and dunes.

The impact basin is named after the Italian astronomer Giovanni Schiaparelli. He is best-known for his observations of Mars, including an 1877 map of the planet that showed straight dark lines he interpreted as natural water-filled channels called “canali” in Italian. Some people thought he meant artificial irrigation canals, leading them to believe they were created by intelligent Martians.

We now know that the “canali” were just illusions created by the telescope technology of the time, and that there are no water-filled canals on the Red Planet. But the latest images from Mars Express add to mounting evidence that the planet had a watery past that helped shape and sculpt the planet we view today.

More information on Mars’ watery past and present:

* Young Mars crater contains water ice, photo shows * Water reshaped Mars more widely than thought * Water on Mars announced 10 years ago * Some Mars channels carved by lava, not water * NASA confirms water on Mars * Gullies mark most recent water flow on Mars * Once-habitable lake found on Mars

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John Roach is a contributing writer for Connect with the Cosmic Log community by hitting the “like” button on the Cosmic Log Facebook page or following’s science editor, Alan Boyle, on Twitter (@b0yle).


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