Ancient Mars lake had microbe-friendly conditions

Alain Brian
Juin 6, 2017

The researchers speculate that different layers of the lake had varying levels of oxygen, which is similar to the lakes on Earth. Studying these rocks could help scientists understand the ultimate drying of Mars as its water escaped to space, leaving the salts behind. "So there's still a lot to work out in trying to reconcile the evidence for more water". It is based on comparing differences in the chemical composition of layers of mud-rich sedimentary rock that were deposited in quiet waters of the lake. Scientists used that data to determine how much oxygen and what kind of environments once existed there.

This is why the Mars rover's wheels were designed with very high surface area, so that the giant vehicle does not get stuck in the sand and at the same time, is able to climb the rocky terrain easily.

This oxidant stratification constituted very different, co-existing environments in the same water body, says lead author Joel Hurowitz.

"Even when the lake eventually evaporated, substantial amounts of groundwater were present for much longer than we previously thought-thus further expanding the window for when life might have existed on Mars", said Frydenvang. Dr. Hurowitz noted, because of these diverse environments, there would have been several chances for various microbes - including those that thrive in oxidant-rich conditions - to survive in the lake.

"Our result is consistent with a warm and wet early Mars climate and the existence of an ancient northern ocean", their study in the journal Nature Communications says.

A simulation depicts a lake partially filling Mars Gale Crater. The varying chemical environments could have provided a home to a many different types of microorganisms. Some microbes thrive in low-oxygen environments, while other prefer the opposite. Scientists by using data from the Curiosity rover mission discovered that the lake, located in the Gale Crater on Mars was stratified which means the water confirmed the evidence of pointed chemical or physical dissimilarities in various parts of the lake. Here, as on Earth, have been key components of life, which was also observed on the Blue planet.

'These oxidation states would be controlled by the dissolved oxygen content of the water'.

Kelly believes that solving the technological problems is not the hard part, but rather that "getting to Mars is more about the political science than the rocket science". Take a look on NASA's website for a hi-res version of the image.

Researchers were surprised by the accuracy of the Curiosity analysis, and how much we can deduct from that.

A hypothesized model of a redox-stratified lake in Gale crater - just like a lake on Earth.

The MRO was responsible for finding evidence of water on Mars, besides being able to find the ideal landing spot for the Curiosity rover. Within the samples were many elements including nitrogen, phosphate minerals, and organic carbon compounds, as well as sulfur and iron.

As for whether Mars does host life now, unfortunately, that's not an answer Curiosity is equipped to answer. Most recently, NASA sent Curiosity, a car-sized robotic rover exploring Gale Crater on Mars.

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