After NASA confirmed that there was flowing liquid on Mars, scientists published a new study suggesting that two tsunamis wipe out red planet’s shorelines billion of years ago.
Scientists from Arizona, in a paper published in Nature Scientific Reports by Planetary Science Institute, point out geologic evidence that suggests that nearly 3.4 billion years ago two tsunamis of about 400 feet high wiped away ancient Martian shorelines, The Washington Post reported.
According to senior scientist J. Alexis Palmero Rodriguez, the enormous waves were triggered by asteroids impacts. As a consequence, Mars’ shorelines were completely wiped out. They say this is the reason why scientists have been struggling to identify the shorelines. Lead author Alexis Rodriguez of the Planetary Science Institute said that the waves may have reached from 100 to 400 feet high. The first tsunami would have covered more than 300,000 square miles of the red planet. Then, a few million years later, a second one covered about 400,000 square miles, he said.
Trough geographical and thermal images to analyze the surface, Arizona scientists finally found out an explanation for the problem they’d been struggling with.
“Widespread tsunami deposits distributed within a wide range of elevations likely characterize the shorelines of early Martian oceans,” Rodriguez said.
In case the hypothesis of Rodriguez and his colleagues is correct, it would mean that the shores of these ancient oceans have been hidden under the unusual geographic structures of the tsunamis, The Washington Post noted. Scientists have found piles of rocks debris caught up against slopes, also known as lobates, which are signs of flowing water up a steep incline with enough force to carry large boulders up to dozens of miles. Rodriguez said that tsunamis are the most likely fitting explanation for what they found, mostly because it’s really hard to find a process in nature able to form this features.
Mars’ climate change
Rodriguez and one of the paper’s co-author, Thomas Platz, unveiled that Mars’ climate became considerably cooler because of a recession of the ocean during the time period in between the two tsunamis. Scientists believe that maybe the ocean began to partially freeze. According to Fox News, evidence found shows that the second tsunami was primarily made of water-ice.
Co-author Alberto Fairén, a Cornell visiting scientist in astronomy and principal investigator at the Center for Astrobiology in Madrid, hypothesized that lobes froze on the land when they reached their maximum extent and the ice never got back to the ocean. Meaning that, at a time, the ocean was at least partially frozen.
“Our paper provides very solid evidence for the existence of very cold oceans on early Mars. It is difficult to imagine Californian beaches on ancient Mars, but try to picture the Great Lakes on a particularly cold and long winter, and that could be a more accurate image of water forming seas and oceans on ancient Mars,” he added.
Scientists believe that having more samples of the areas, they would likely find frozen ancient ocean water brines, which will allow them to obtain information about the primary composition of the ocean. They also think that the fact that the water may be frozen since the tsunamis occurred, could make it an ideal place for microbial life searching. If any microbes could evolve and thrive in the oceans of Mars, it’s likely that traces of them are trapped in those lobates.
Scientists may not get the samples they need for continuing their investigation anytime soon
Scientists are betting on the Mars Pathfinder to find and test materials because the areas of interests are close to the rover’s landing site. Rodriguez said that they have already identified some of the areas that were inundated by both tsunamis and where the ponded water seems to have emplaced lacustrine sediments, and evaporates. He adds that for future investigations they are planning a characterization of these terrains and assess their potential for upcoming robotic or human in-situ exploration.
Fairén, Rodriguez and their colleagues are planning to hunt Martian maps in order to search for more features that could be linked to tsunamis, such as lakes formed as tsunamis splashed into impact craters and salt deposits left behind as water receded. Regarding this, The Washington Post informed that Rodriguez and co-author Jianguo Yan of Wuhan University will go to Tibet for an expedition. They believe that there are lakes up high in the mountains that show similarities to the supposedly tsunami-induced lakes on Mars.
However, according to The Washington Post’s report, NASA and other space agencies follow strict rules to determinate where their space robots can and cannot explore. Areas that they consider potentially habitable are off-limits as a precaution. They fear some tenacious Earth microbe could invade and invalidate any samples they test on Mars, even when they make sure its rovers are as sterile as they can be before leaving home.
Some scientists disagree with the studies made. They believe that the features are a consequence of another ancient phenomenon.
Source: PSI