The colossal ‘planet killer’ asteroid caused a mega tsunami on Mars, and now we know where it landed
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A newly discovered impact crater on Mars was likely left behind by a huge asteroid that smashed into the Red Planet around 3.4 billion years ago and may have unleashed an 800-foot-tall “mega-tsunami.” The colossal explosion was similar to an asteroid impact on Earth that wiped out non-avian dinosaurs, a new study shows.
From about 3,500 million to 3,000 million years ago, Mars it was covered by vast, shallow oceans. During that time, one of these oceans, which once covered the northern lowlands of Mars (Vastitas Borealis), experienced multiple mega-tsunamis when asteroids crashed into the ancient body of water, according to POT (opens in a new tab).
Previous research has found evidence of at least two massive wave events on the ancient coastline that once encircled the long-lost ocean, including large chunks of debris washing ashore and rock markings that likely formed as the displaced water slowly drained into the ocean. The first event probably occurred about 3.4 billion years ago, and the second probably arose about 3 billion years ago when the oceans of Mars began to dry up, according to NASA.
Related: The oldest meteorite on Mars dates back to a strange double-impact crater
In a new study, published December 1 in the journal scientific reports (opens in a new tab), planetary scientists identified a new impact crater, called Pohl, which is a very plausible candidate for the first of the mega-tsunamis. Pohl is about 68 miles (110 kilometers) wide and lies about 394 feet (120 meters) below suspected sea level at the time. The massive impact structure is also surrounded by 3.4 billion-year-old rocks.
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Based on Pohl’s size, researchers estimate that the asteroid responsible for the crater’s birth spanned between 1.9 and 5.6 miles (3 to 9 km) and released up to 13 million megatons of TNT energy. For context, the most powerful nuclear bomb Never detonated on Earth, the Czar’s bomb released about 50 megatons of TNT energy.
The study team then used computer simulations to recreate the massive wave that would have been generated by this colossal impact. They found that the waves could have reached up to 820 feet (250 m) in height and traveled about 932 miles (1,500 km) from the crater. These waves would have been large enough to outpace geological evidence already discovered by previous researchers, the team said in a statement. declaration (opens in a new tab).
Related: Giant ‘hidden water’ reservoir discovered on Mars
This gigantic impact structure has some key similarities to the Chicxulub box, which was left behind by an asteroid impact that triggered a mass extinction event about 66 million years ago and wiped out non-avian dinosaurs, the researchers wrote.
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Chicxulub crater, located on Mexico’s Yucatan Peninsula, is significantly larger than Pohl, spanning around 112 miles (180 km), and was birthed by a larger asteroid that was around 7.5 miles (12 km) wide. The Chicxulub asteroid also touched down on top of an ancient ocean on Earth that was around 656 feet (200 m) deep at the time. In October, a pair of unrelated studies found that the impact of Chicxulub also triggered a mega-tsunami with waves a mile high and triggered a megaquake that shook the planet for months.
This is not the first time that researchers have identified a potential impact crater for Martian mega-tsunamis. In 2019, a separate team of researchers proposed that the Lomonosov crater, which measures around 90 miles (145 km) across, was left behind by an impactor that could have caused a mega-tsunami.
However, Lomonosov crater has not been precisely dated, so it is unclear what megatsunami might have triggered the impactor or if the impact occurred when oceans were present.