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A newly discovered impact crater on Mars was likely left behind by a massive asteroid that slammed into the Red Planet around 3.4 billion years ago and may have triggered an 800ft ‘mega-tsunami’ high. The colossal explosion was similar to the asteroid impact on Earth that wiped out non-avian dinosaurs, according to a new study.
About 3.5 to 3 billion years ago, Mars was covered in vast, shallow oceans. Meanwhile, one of those oceans, which once covered Mars’ northern lowlands (Vastitas Borealis), experienced several mega-tsunamis when asteroids slammed into the ancient body of water, according to Nasa (opens in a new tab).
Previous research has found evidence of at least two massive waves on the ancient shoreline that once surrounded the long-lost ocean, including large chunks of debris that washed ashore and rock marks that washed ashore. probably dug out when the displaced water slowly drained into the ocean. The first event likely happened about 3.4 billion years ago, and the second likely appeared about 3 billion years ago when Mars’ oceans began to dry up, according to NASA .
Related: Mars’ oldest meteorite found in bizarre double-impact crater
In a new study, published Dec. 1 in the journal Scientific reports (opens in a new tab), planetary scientists have identified a new impact crater, named Pohl, which is a very plausible candidate for the first of the mega-tsunamis. Pohl is around 110 kilometers wide and lies around 120 meters below the then suspected sea level. The massive impact structure is also surrounded by 3.4 billion year old rocks.
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Based on Pohl’s size, the researchers estimate that the asteroid responsible for the crater’s birth extended between 1.9 and 5.6 miles (3 to 9 km) and released up to 13 million megatons TNT energy. For context, the most powerful nuclear bomb never detonated on Earth, the Tsar Bomb, released approximately 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 reach up to 820 feet (250 m) high and travel about 932 miles (1,500 km) from the crater. These waves would have been large enough to leave behind geological evidence already discovered by earlier researchers, the team said in a statement. statement (opens in a new tab).
Related: Giant reservoir of ‘hidden water’ discovered on Mars
This gargantuan impact structure bears key similarities to the Chicxulub crate, which was left behind by an asteroid impact that triggered a mass extinction event around 66 million years ago and wiped out the dinosaurs not avians, the researchers wrote.
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The Chicxulub crater, located on Mexico’s Yucatán Peninsula, is significantly larger than Pohl, spanning about 180 km, and was spawned by a larger asteroid about 12 km in diameter. The Chicxulub asteroid also landed on top of an ancient ocean on Earth that was around 656 feet (200 m) deep at the time. In October, a pair of independent studies revealed that the impact of Chicxulub triggered a mega-tsunami with kilometer high waves and triggered a mega-earthquake that shook the planet for months.
This isn’t the first time 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 145 km in diameter, was left by an impactor that could have triggered a mega-tsunami.
However, the Lomonosov crater has not been precisely dated, so it is unclear which mega-tsunami the impactor might have triggered or whether the impact occurred while oceans were present.
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