Mount Sharp rises three miles above the Martian surface thanks to millions of years of sediment deposits. “Where there’s now a mountain, there may have once been a series of lakes,” says Curiosity Project Scientist John Grotzinger.
“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,” said Ashwin Vasavada, Curiosity deputy project scientist at NASA’s Jet Propulsion Laboratory in Pasadena. “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.”
Answering the question of why Mount Sharp sits in a crater has been one of the primary tasks for Curiosity. Mount Sharp is made up of layered sediments that alternate between wind, lake and river deposits according to NASA scientists. Here’s an illustration showing a lake of water filling Mars’ Gale Crater.
Right now, Curiosity is examining the lowest sedimentary layers of Mount Sharp. It’s a 500 feet section of rock called the Murray formation.
Mount Sharp’s sediment layers eventually hardened into rock overtime and wind erosion gave it its shape today.
“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,” Grotzinger said. “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. 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.”
There’s still a lot scientists don’t know about Mars. Various Mars missions have shown evidence pointing to wet environments on the red planet. Yet, the conditions for periods long enough for water to exist on the surface of the planet can’t be identified.
Curiosity will continue its trek up Mount Sharp in the coming months. We’ll keep you posted on any new discoveries or changes to NASA’s hypothesis.
Image credits: NASA