A megatsunami on Mars was likely caused by an asteroid impact like the Chicxulub collision—a massive asteroid impact that led to the mass extinction of most dinosaurs on Earth—that happened in a shallow ocean region.
Previously, researchers have proposed that an asteroid impact on a Martian ocean in the northern lowlands caused a tsunami around three billion years ago. For the new study published in the journal Scientific Reports, researchers analysed maps of Mars’s surface which were created using images from previous missions to the planet. Prior to this study, the location of the impact crater was unclear.
The crater in question has a diameter of 110 kilometres and is located in a region that previous studies suggests may have been covered by an ocean. The authors of the new study suggest that this crater may have formed around 3.4 billion years ago by an asteroid collision.
In order to come to this conclusion, the researchers simulated asteroid collisions in this region to find out what type of impact could have caused this crater and led to the megatsunami. The simulations revealed that similar craters could be caused by either a nine-kilometre asteroid that encountered strong ground resistance or a three kilometres asteroid encountering weak ground resistance. Such collisions could release 13 million megatons of TNT energy or 0.5 million megatons of TNT energy respectively.
For comparison, the Tsar Bomba, the most powerful thermonuclear weapon ever tested, generated energy worth approximately 57 tons of TNT energy. But both these hypothetical impacts would generate craters measuring 110 kilometres in diameter while causing tsunamis that reach as far as 1,500 kilometres from the impact site.
The scientists suggest that this impact could have had a lot of similarities with the Chicxulub impact, which according to scientists could have triggered massive megatsunamis and earthquakes.