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Science: Water Acted Regionally on Ancient Mars, Not Just Locally
False color image of Cape St. Vincent at Victoria Crater, Mars.
[Image courtesy of Steven W. Squyres]
New data from the Mars rover Opportunity shows that the pattern of sedimentary layers in the Victoria crater on Mars, shaped by ancient water flow, is similar to patterns found in other craters more than three and a half miles (six kilometers) to the north. According to researchers, this finding means that water once helped to shape that entire region of the planet long ago.
The Victoria crater sits near the Martian equator, and Opportunity has been exploring the site for about the past two years. The crater is approximately 750 meters in diameter and 75 meters deep.
Before reaching the Victoria crater, the Opportunity rover examined two separate craters—Eagle and Endurance—located miles to the north of Victoria.
Using data relayed to Earth from Opportunity, Steven Squyres from Cornell University, along with colleagues from various organizations, agencies, and universities across the United States, characterized the meteoric impact that created the Victoria crater. In their report, published 22 May in Science, they also highlight the ancient flow of water that once carved through the region, and compare it to the processes that had worked at the Eagle and Endurance craters.
The researchers examined a section of the Victoria crater more than 10 meters thick, and observed that the layering of sulfate-rich sedimentary rocks in the crater walls show evidence of ancient wind-blown dunes, comparable in scale to those deposited in the western United States during the Jurassic period, about 200—146 million years ago.
Their most significant finding, however, was that the ancient water-induced alteration processes that were documented at the two other craters on Mars, miles away, had also acted on the Victoria site to shape the terrain there. This means that the same water that once cut through the ground at the Victoria crater's site acted regionally, not just locally, to likewise shape the planet many miles away.
21 May 2009