Field Geology on Mars Reveals Evidence of Megaflood

Guest “field geology rocks!” by David Middleton

Field geology at Mars’ equator points to ancient megaflood
By Blaine Friedlander | November 18, 2020

Floods of unimaginable magnitude once washed through Gale Crater on Mars’ equator around 4 billion years ago – a finding that hints at the possibility that life may have existed there, according to data collected by NASA’s Curiosity rover and analyzed in joint project by scientists from Jackson State University, Cornell, the Jet Propulsion Laboratory and the University of Hawaii.

The research, “Deposits from Giant Floods in Gale Crater and Their Implications for the Climate of Early Mars,” was published Nov. 5 in Nature Scientific Reports.

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“We identified megafloods for the first time using detailed sedimentological data observed by the rover Curiosity,” said co-author Alberto G. Fairén, a visiting astrobiologist in the College of Arts and Sciences. “Deposits left behind by megafloods had not been previously identified with orbiter data.”

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The most likely cause of the Mars flooding was the melting of ice from heat generated by a large impact, which released carbon dioxide and methane from the planet’s frozen reservoirs. The water vapor and release of gases combined to produce a short period of warm and wet conditions on the red planet.

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The Curiosity rover science team has already established that Gale Crater once had persistent lakes and streams in the ancient past. These long-lived bodies of water are good indicators that the crater, as well as Mount Sharp within it, were capable of supporting microbial life.

“Early Mars was an extremely active planet from a geological point of view,” Fairén said. “The planet had the conditions needed to support the presence of liquid water on the surface – and on Earth, where there’s water, there’s life.

“So early Mars was a habitable planet,” he said. “Was it inhabited? That’s a question that the next rover Perseverance … will help to answer.”

Perseverance, which launched from Cape Canaveral on July 30, is scheduled to reach Mars on Feb. 18, 2021.

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Cornell Chronicle

“This composite, false-color image of Mount Sharp inside Gale crater on Mars shows geologists a changing planetary environment. On Mars, the sky is not blue, but the image was made to resemble Earth so that scientists could distinguish stratification layers. NASA/JPL/Provided” (Cornell Chronicle)

The full text of the excellent paper is available:

Heydari, E., Schroeder, J.F., Calef, F.J. et al. Deposits from giant floods in Gale crater and their implications for the climate of early Mars. Sci Rep 10, 19099 (2020). https://doi.org/10.1038/s41598-020-75665-7

As cool as the geology of Gale Crater has been, Jezero Crater promises to even cooler. Perseverance is about two thirds of the way there and will be an even more capable field geologist than Curiosity has been.

Mars Perseverance rover scientific instruments. (NASA)

Mastcam-Z has powerful cameras that can zoom in, focus, and take color 3-D images and video at high speed to allow detailed examination of distant objects.

MEDA, the Mars environmental dynamics analyzer, is a weather station that measures wind speed and direction, temperature and humidity, and the size and amount of dust particles in the Martian atmosphere.

MOXIE, the Mars oxygen in-situ resource utilization experiment, will demonstrate technology to produce oxygen from the Martian atmosphere for propellant and for breathing air for future human explorers.

PIXL, the planetary instrument for X-ray lithochemistry, is an X-ray spectrometer used to identify chemical composition at a tiny scale. This will allow scientists to look for organic chemicals of possible past microbial life on Mars.

RIMFAX, the radar imager for Mars’ subsurface experiment, is a ground-penetrating radar system that will probe the geology below the rover to a depth of ten meters. RIMFAX will be used to detect ice, water and salty brines.

SHERLOC, the instrument for scanning habitable environments with Raman spectroscopy and luminescence for organics and chemicals, uses spectrometers, a laser and a camera to search for organic chemicals and minerals that may be signs of past microbial life from a wet environment.

SuperCam will examine rocks and soils with a camera, laser and spectrometers to find organic chemicals from possible past life on Mars. It can focus on targets as small as a sand grain from a distance up to seven meters.

Ingenuity UAV helicopter: In addition to this sophisticated instrument suite, Perseverance carries the small UAV helicopter, named Ingenuity, attached to the rover’s belly. It will be deployed for several flights up to 10 meters high and ranging up to 300 meters away from the rover to scout for science targets and driving routes.

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