#astronomy Curiosity closing in on Mars’ transition from moist to dry – Astronomy Now

October 9, 2019 - Comment

This animation reveals how ponds and lakes in Gale Crater could have stuffed, dried out and stuffed once more over tens of millions of years as Mars transitioned from a liveable world to the frigid desert seen right this moment. Picture: ASU Data Enterprise Growth (KED), Michael Northrop Some three.5 billion years in the past,



This animation reveals how ponds and lakes in Gale Crater could have stuffed, dried out and stuffed once more over tens of millions of years as Mars transitioned from a liveable world to the frigid desert seen right this moment. Picture: ASU Data Enterprise Growth (KED), Michael Northrop

Some three.5 billion years in the past, ponds fed by streams within the partitions of Gale Crater doubtless went via cycles because the waterways flowed, dried up after which flowed once more over tens of millions of years through the planet’s transition from a hotter, wetter world to the frozen desert seen right this moment.

In a paper revealed by Nature Geoscience, researchers with the Mars Curiosity rover interpret rocks laced with mineral sals as indicators of shallow, briny ponds that went via episodic filling and drying. That could be the results of local weather fluctuations occurring because the martian atmosphere made that transition.

Discovering out when and why it occurred are main goals relating to deciphering the historical past of Mars.

Curiosity landed on the ground of Gale Crater in 2012 and is slowly making its method up the decrease slopes of Mount Sharp, a towering mound of sedimentary rock and soil on the coronary heart of the 150-kilometre-wide (100-mile-wide) influence crater.

Information collected from orbit point out rock within the decrease areas of the mountain fashioned in a local weather that will have been liveable within the distant previous. Rocks within the greater areas seem to characterize a a lot drier local weather. Curiosity could assist pinpoint when that transition occurred because it continues its trek up the slopes.

“We went to Gale Crater as a result of it preserves this distinctive file of a altering Mars,” mentioned lead creator William Rapin of Caltech. “Understanding when and the way the planet’s local weather began evolving is a bit of one other puzzle: When and the way lengthy was Mars able to supporting microbial life on the floor?”

Rapin and his colleagues focus on salts present in a 150-metre-tall (500-foot-tall) formation often called Sutton Island that was studied by Curiosity in 2017. The salts recommend water that after pooled within the space was concentrated into brine, presumably crystallising simply beneath evaporating ponds of briny water.

Comparable saline lakes and ponds will be discovered on Earth in South America’s high-altitude Altiplano plain, fed by rivers and streams flowing from close by mountains within the Andes.

“Throughout drier durations, the Altiplano lakes change into shallower, and a few can dry out utterly,” Rapin mentioned. “The truth that they’re vegetation-free even makes them look a bit like Mars.”

Curiosity is presently heading towards a area often called the “sulphate-bearing unit” that doubtless fashioned in a a lot drier atmosphere, starkly completely different from decrease areas the place the rover discovered sediments indicating the previous presence of fresh-water lakes.

“As we climb Mount Sharp, we see an general pattern from a moist panorama to a drier one,” mentioned Ashwin Vasavada, Curiosity challenge scientist on the Jet Propulsion Laboratory. “However that pattern didn’t essentially happen in a linear trend. Extra doubtless, it was messy, together with drier durations, like what we’re seeing at Sutton Island, adopted by wetter durations, like what we’re seeing within the ‘clay-bearing unit’ that Curiosity is exploring right this moment.”



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