Perserverances view over the Jezero crater towards the old river delta.
NASA / JPL-Caltech
Mars rovers could soon get a few new checkpoints to explore. Geologists say certain areas of an ancient river delta near NASA’s Perseverance rover station on the rocky red planet may contain fossilized evidence of extraterrestrial life.
While they don’t expect to find any green bug-eyed aliens, they say vital organic compounds may exist there, suggesting that previous life is there to be discovered.
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The research crew behind the new study, published Thursday in Science journal, dissected photos ofand discovered how water flowed on Mars billions of years ago.
Their analysis revealed places on the dry sphere that could harbor the coveted biosignatures.
“We know that water flowed on the surface in the past, but we don’t know how long this activity lasted,” said the study’s lead author, Nicolas Mangold, a geologist at the University of Nantes in France.
The Persistence of NASA and the Legend of Jezero
Once upon a time in space, Mars was not a dry and dangerous world. It was covered with fresh rivers and lakes similar to those on Earth. And where there is water, there could also be life.
The huge H2O bodies dried up eons ago when the fragile atmosphere of the once blue planet disappeared. This turned the environment into the inhospitable land we know today.
Scientists have long been fascinated by the earlier existence of water on Mars. Because of this, NASA sent Perseverance to traverse the planet in hopes of finding fingerprints of life. More specifically, they sent the rover to a huge crater called Jezero.
This image from the Mars Reconnaissance Orbiter shows the delta region of the Jezero crater.
NASA / JPL-Caltech / MSSS / JHU-APL
Jezero Crater is believed to have been flooded by water and is home to an ancient river delta – a delta that could contain signs of extraterrestrial life.
Deltas are landforms that are created by rocks and sediments that are carried away by a river. This stream often carries organic molecules and bacteria on its way, which means that the Jezero Delta could easily contain an accumulation of such materials.
In other words, it could contain petrified building blocks of life.
With this in mind, the points of interest proposed by the study team for finding evidence of life on Mars are all anchored in this delta. At first, says Mangold, he hoped Perseverance would capture clear images of the place, but unfortunately Percy is a little too far from the old river for that.
“Despite our disappointment,” he said, “we have tried to view the Delta from a distance with our best cameras and it has produced wonderful results.”
Notes from Kodiak
Surprisingly, the researchers found the coveted areas not just by analyzing the main Jezero delta. They observed a nearby hill or rock mound called Kodiak. Kodiak is a bit more distant part of the delta.
“You can imagine that the delta was expanded a little to the south and east, then the erosion removed part of the material,” says Mangold. “But Kodiak is miraculously preserved.”
Kodiak serves as a geological representation of the features of the main river delta. According to the researchers, the stratigraphy, its rock layers, can be seen relatively easily from a distance.
“By understanding stratigraphy at Kodiak, we can identify the deposits that are most likely of life support,” said Mangold.
He described the team’s first look at the photos as a “shock”.
“The first picture is actually [one] where we can see boulders, “he said.” A delta error … shouldn’t get big boulders. It should be consistent. “
These boulders, he said, mean that the Jezero river delta is a Gilbert-type delta. These are formed by stronger water currents such as waves and tides, such as those found in a lake. Hence, the team believes that the flow of the river suddenly became more intense over the course of its life.
“A big question for us,” said Mangold, “is to understand why this change in hydrological activity occurred because that is probably the signature of climate change.”
Kodiak also offered a glimpse of the height of the ancient body of water. Mangold says it would have been about 2,500 feet high based on the strip of rock in the butte. That altitude has changed over time, he says, which is also in line with the idea that the river became a lake.
“That kind of observation is really important,” he said. “Because it shows that there was a lake in Jezero, there is no doubt about it … and the change from the horizontal stratification to the stratified faults indicates the past water level.”
In the end, all of this knowledge led Mangold’s team to isolate places where remnants of life could be found – deeper layers of Kodiak that likely have mud-dominated debris as well as grains of sand. These types of sediments are known to contain organic, life-sustaining molecules.
“Kodiak isn’t easy to get to with the rover because it’s a bit vertical,” noted Mangold.
“But we have identified a few locations on the main delta fault where we can access similar types of layers. These locations are some of our favorite destinations for future rover trips.”