“Early Mars was an extremely active planet from a geological point of view,” said Alberto G. Fairén, a visiting astrobiologist at Cornell University. “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.”
Probing Gale Crater–Thickest Exposed Sedimentary Rocks in the Solar System
The Curiosity rover science team currently in place at Gale Crater –Gale Crater, an immense 96-mile-wide rocky basin–with its strangely sculpted mountain –three times higher than the Grand Canyon is deep– that is being explored with the NASA Curiosity rover since 2012 as part of the MSL (Mars Science Laboratory) mission– has already established that the crater 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.
Gale Crater may be” one of the thickest exposed sections of layered sedimentary rocks in the solar system,” said Joy Crisp, MSL Deputy Project Scientist from NASA’s Jet Propulsion Laboratory in 2011. “The rock record preserved in those layers holds stories that are billions of years old — stories about whether, when, and for how long Mars might have been habitable.”
Raging Megaflood 4 Billion Years Ago
Cornell University reaserchers have announced that a raging megaflood likely triggered by the heat of a meteoritic impact, unleashed ice stored on the Martian surface, releasing carbon dioxide and methane from the planet’s frozen reservoirs, and set up gigantic ripples that are tell-tale geologic structures familiar to scientists on Earth. The floods of unimaginable magnitude that washed through Gale Crater on Mars’ equator around 4 billion years ago – 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 University, the Jet Propulsion Laboratory and the University of Hawaii. The water vapor and release of gases by the impact combined to produce a short period of warm and wet conditions on the red planet.
This composite, false-color image above 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.
“We identified megafloods for the first time using detailed sedimentological data observed by the rover Curiosity,” said co-author Fairén. “Deposits left behind by megafloods had not been previously identified with orbiter data.”
Megaripples & Antidunes
This case includes the occurrence of giant wave-shaped features in sedimentary layers of Gale crater, often called “megaripples” or antidunes that are about 30-feet high and spaced about 450 feet apart, according to lead author Ezat Heydari, a professor of physics at Jackson State University. The antidunes, reports Cornell, are indicative of flowing megafloods at the bottom of Mars’ Gale Crater about 4 billion years ago, which are identical to the features formed by melting ice on Earth about 2 million years ago, Heydari said.
Planetwide Torrential Rain
Condensation formed water vapor clouds, which in turn created torrential rain, possibly planetwide. That water entered Gale Crater, then combined with water coming down from Mount Sharp (in Gale Crater) to produce gigantic flash floods that deposited the gravel ridges in the Hummocky Plains Unit and the ridge-and-trough band formations in the Striated Unit.
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.
“So early Mars was a habitable planet,” Heydari asks. “Was it inhabited? That’s a question that the next NASA rover, Perseverance will help to answer.” Perseverance, which launched from Cape Canaveral on July 30, is scheduled to reach Mars on Feb. 18, 2021.
The research, “Deposits from Giant Floods in Gale Crater and Their Implications for the Climate of Early Mars,” was published Nov. 5 in Scientific Reports.