Scientists say the impact on Mars was similar to the Chicxulub impact 66 million years ago that wiped out the dinosaurs on Earth.
A Martian megatsunami was likely caused by a large asteroid impact when Mars was more similar to Earth. Scientists say the impact was similar to the Chicxulub impact 66 million years ago that wiped out the dinosaurs on Earth. According to a study published in Scientific Reports, ancient Mars harbored an ocean in the northern lowlands. Those Martian lowlands are home to a massive impact crater. About 3.4 billion years ago, a gigantic space rock struck the red planet. It was either a comet or an asteroid. The impact was so powerful it unleashed a massive megatsunami on Mars. It was unclear, however, where the impact crater would be located before this study. An impact crater that may have caused the megatsunami was identified by Alexis Rodriguez and colleagues at the Institute of Planetary Sciences in Tucson.
The crater identified by scientists is 110 kilometers across and located in an area of the northern lowlands that was previously thought to have been underwater, about 120 meters below the proposed sea level. The crater has been named Pohl. Based on the position of Pohl above and below rocks previously dated to the same period, the authors suggest Pohl formed around 3.4 billion years ago. To determine whether Pohl could have caused a megatsunami, the authors simulated collisions between asteroids and comets in this region. According to the researchers, simulations that generated craters similar to Pohl’s resulted from two possibilities.
One possibility is that it was formed by a nine-kilometer asteroid encountering substantial drag. This space rock would have released 13 million megatons of TNT energy. The second possibility is that it formed from a three-kilometer asteroid encountering weak resistance to the ground. This would have released 0.5 million megatons of TNT energy. It is estimated that approximately 57 megatons of TNT energy was released by the Soviet Tsar, the most powerful nuclear bomb ever tested. There were megatsunamis that reached up to 1,500 kilometers from the center of both simulated impacts. The craters were 110 kilometers across.