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Oblique view of the Gale crater, Mars, with vertical exaggeration. The image combines elevation data from the high-resolution stereo camera on the European Space Agency’s Mars Express orbiter, image data from the Context Camera on NASA’s Mars Reconnaissance Orbiter, and color information from Viking Orbiter images. Credits: NASA / JPL-Caltech / ESA / DLR / FU Berlin / MSSS
The geology of the field at the equator of Mars indicates an ancient megaflood
Floods of unimaginable size once poured through Gale Crater Marsequator about 4 billion years ago – a discovery that suggests the possibility that life may have existed there, according to data collected by NASA‘s Curiosity rover is being analyzed in a 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 November 5, 2020 in Nature Scientific reports.
The furious mega flood – likely caused by the heat of a meteor impact, which released the ice stored on the Martian surface – created giant ripples that are telltale geological structures familiar to scientists on Earth.
“We identified megafloods for the first time using detailed sedimentological data observed by the Curiosity rover,” said co-author Alberto G. Fairén, a visiting astrobiologist at the College of Arts and Sciences. “The deposits left by the megafloods had not previously been identified with the orbiting data.”
As in the case of the Earth, geological features, including the work of water and wind, have been frozen in time on Mars for about 4 billion years. These features convey processes that have shaped the surface of both planets in the past.
This false-color composite image of Mount Sharp inside the Gale Crater on Mars shows geologists an evolving planetary environment. On Mars, the sky isn’t blue, but the image was made to resemble the Earth so that scientists could distinguish the layering layers. Credit: NASA / JPL
This case includes the occurrence of gigantic wave-shaped features in the sedimentary layers of the Gale crater, often called “megaripples” or antidunes that are about 30 feet tall and spaced about 450 feet apart, according to the lead author. Ezat Heydari, a physics professor at Jackson State University.
Antidunes are indicative of megafloods flowing at the bottom of Mars’ Gale crater about 4 billion years ago, which are identical to features formed by the melting of ice on Earth about 2 million years ago, Heydari said.
The most likely cause of the flooding of Mars was the melting of the ice caused by the heat generated by a large impact, which released carbon dioxide and methane from the planet’s frozen reservoirs. Water vapor and the release of gases combined to produce a short period of warm, humid conditions on the red planet.
The condensation formed clouds of water vapor, which in turn created torrential rains, possibly all over the planet. That water entered the Gale Crater, then combined with the water flowing down from Mount Sharp (in the Gale Crater) to produce gigantic flash floods that deposited the gravel ridges in the Hummocky Plains drive and the ridge band formations and depressions in the Striated Unit.
The science team of the Curiosity rover 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 geologic point of view,” Fairén said. “The planet had the necessary conditions to support the presence of liquid water on the surface and on the Earth, where there is water, there is life.
“So early Mars was a habitable planet,” he said. “Was it inhabited? This is a question that the next Perseverance rover … will help answer. “
Perseverance, launched from Cape Canaveral on July 30, is expected to reach Mars on February 18, 2021.
Reference: “Giant Flood Deposits in Gale Crater and Their Implications for Early Mars Climate” by E. Heydari, JF Schroeder, FJ Calef, J. Van Beek, SK Rowland, TJ Parker and AG Fairén, 5 November 2020, Scientific reports.
DOI: 10.1038 / s41598-020-75665-7
Joining Fairén and Heydari on paper are Jeffrey F. Schroeder, Fred J. Calef, Jason Van Beek, and Timothy J. Parker, of NASA’s Jet Propulsion Laboratory; and Scott K. Rowland, University of Hawaii.
Data and funding were provided by NASA, Malin Space Science Systems, the Jet Propulsion Laboratory and the European Research Council.
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