Curiosity Finds Evidence That Water Helped Form Mars' Mount Sharp

Chuck Bednar for redOrbit.com – Your Universe Online

Sediments deposited in a large lake bed over tens of millions of years were responsible for the creation of Mount Sharp on Mars, according to observations conducted by NASA’s Curiosity Rover in Gale Crater.

This interpretation of the rover’s findings suggest that the Red Planet had once maintained a climate capable of producing long-lasting lakes at several different locations, Curiosity deputy project scientist Ashwin Vasavada and his colleagues revealed in a statement on Monday.

“If our hypothesis for Mount Sharp holds up, it challenges the notion that warm and wet conditions were transient, local, or only underground on Mars,” explained Vasavada, who works at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. “A more radical explanation is that Mars’ ancient, thicker atmosphere raised temperatures above freezing globally, but so far we don’t know how the atmosphere did that.”

Researchers have struggled with explaining why the three-mile tall Mount Sharp rests in a crater, with its lower flanks exposing hundreds of rock layers. Those layers, which alternate between lake, river and wind deposits, are evidence of the repeated filling and evaporating of a Martian lake larger and longer-lasting than any previously detected.

Curiosity is currently in the process of analyzing the lowest sedimentary layers of Mount Sharp, a section of rock 500 feet high that has been identified as the Murray Formation. NASA scientists believe that sand and silt was carried to the lake by rivers, which then deposited the sediments at the mount of the river. As a result, deltas similar to those found at the mouths of rivers here on Earth formed, and the cycle repeated time and time again.

Once the crater filled to a height of at least a few hundred yards, the sediments hardened into rock, the US space agency explained. Over time, wind erosion sculpted the accumulated layers of sediment into the shape of a mountain, carving away the material between the crater perimeter and what is now the edge of the mountain.

“We are making headway in solving the mystery of Mount Sharp. Where there’s now a mountain, there may have once been a series of lakes,” said Curiosity Project Scientist John Grotzinger of the California Institute of Technology in Pasadena. “The great thing about a lake that occurs repeatedly, over and over, is that each time it comes back it is another experiment to tell you how the environment works.”

“As Curiosity climbs higher on Mount Sharp, we will have a series of experiments to show patterns in how the atmosphere and the water and the sediments interact,” he added. “We may see how the chemistry changed in the lakes over time. This is a hypothesis supported by what we have observed so far, providing a framework for testing in the coming year.”

The discoveries were made during a five-mile journey from Curiosity’s landing site to its current location at the base of Mount Sharp. During that voyage, the rover uncovered various clues about the changing shape of the crater floor when there were lakes on the Red Planet: clues such as sedimentary rocks indicative of small, ancient deltas stacked one on top of another, according to Curiosity science team member Sanjeev Gupta of Imperial College London.

“Despite earlier evidence from several Mars missions that pointed to wet environments on ancient Mars, modeling of the ancient climate has yet to identify the conditions that could have produced long periods warm enough for stable water on the surface,” NASA said, adding Curiosity is being used “to assess ancient, potentially habitable environments and the significant changes the Martian environment has experienced over millions of years.”

The project is one part of NASA’s ongoing Mars research, and will play a key role in the preparation for a planned manned mission to the Red Planet in the 2030s. Michael Meyer, lead scientist for NASA’s Mars Exploration Program at the agency’s headquarters in Washington, noted that the information being gained by this research “will also help guide plans for future missions to seek signs of Martian life.”

—–

Follow redOrbit on Twitter, Facebook, Instagram and Pinterest.

redOrbit.com
offers Science, Space, Technology, Health news, videos, images and
reference information. For the latest science news, space news,
technology news, health news visit redOrbit.com frequently. Learn
something new every day.”