Epicentre of mega-tsunami that rocked Mars 3 bn years ago may have been found

Around 3 billion years ago, an ancient impact on Mars created a global event of epic proportions — a mega-tsunami. Scientists at NASA may have just discovered the epicentre of this ancient flood with some help from their Mars Global Surveyor probe. A 120-kilometre-wide hole in the ground, called the Lomonosov Crater, is a promising candidate for the impact since it fulfils many of the criteria for the meteor that spawned the ancient flood in the Martian Arctic plains, according to a new report. An event of similar scale also took place on Earth in the relatively recent past. Sixty-six million years ago, a 10-km-wide asteroid the size of Lomonosov’s impactor hit the Yucatan Peninsula in Mexico, sparking a mass extinction that wiped out 75 percent of all life and diversity on Earth (including the dinosaurs). [caption id=“attachment_7115911” align=“alignnone” width=“1280”] A chilly Lomonosov crater in the northern hemisphere of Mars as seen by the Mars Global Surveyor probe. Image: NASA[/caption] Mars and Earth are rarely ever struck by asteroids. The new study offers important clues into the ancient ocean that once spread over the red planet. While there don’t appear to be any living organisms on Mars today, there is still evidence suggesting that Mars had the potential to host life in its past. The wide, salty ocean that spread over the Martian North was formed 3.4 billion years ago — its existence widely-accepted by Mars researchers, according to the study’s lead author Alexis Rodriguez, a planetary scientist at the Planetary Science Institute in Arizona. The continuing debate, though, is about what the nature of this ocean was, and what it contained. For instance, one camp of scientists believe that the ocean on Mars was around for many millions of years, provided the temperature on Mars was quite cold. The second camp of experts reckons the ancient climate on Mars wouldn’t have allowed a stable body of water on the surface to last very long, and therefore, propose that the ocean quickly froze over — in the span of a few thousand years. The new study, published in the Journal of Geophysical Research: Planets, lends the former viewpoint support. [caption id=“attachment_7115991” align=“alignnone” width=“1280”] Mars may have had great spots for a beach vacay once upon a time. Image: NASA[/caption] In an earlier paper published by the same group of researchers, they identify large “lobes” in the northern plains on Mars. This is a feature curiously resembling marks left behind by a large water event, like a terrestrial tsunami. The lobes, according to the 2016 study, can be traced back to not one, but two unrelated mega-tsunamis that affected the region over than three billion years ago. While there’s plenty of evidence suggesting that the Lomonosov Crater was the tsunami’s epicentre, it isn’t indisputable yet. “This is possibly the first time that a potential marine crater associated with a tsunami has been investigated outside Earth,” Rodriguez said. “This crater is a candidate. I would not go so far as to say this is definitely the crater that produced the tsunami,” he added. The Crater is now also a tantalizing target for future life-hunting missions. But robotic explorers like Curiosity and the upcoming Mars 2020 aren’t built for the task. Even if waterproof (which they aren’t, for now), the 10-metre-thick ice layer covering the Crater’s surface will be far too tricky for them to drill autonomously. No, this deeper exploration will be a task for human visitors on Mars.