Study: Asteroid impact 3 billion years ago triggered mega-tsunami on Mars

By Mark Waghorn via SWNS

An asteroid impact on Mars more than three billion years ago, similar to the one that wiped out the dinosaurs on Earth, triggered a mega-tsunami on Mars, according to new research.

Resulting in waves that loomed hundreds of feet high and traveled around 1,000 miles - carving out much of the surrounding landscape.

The finding is based on an analysis of a 65-mile-wide crater named Pohl in the northern lowlands.

It adds to evidence the Red Planet was once blue - awash with oceans, rivers and lakes.

Corresponding author Dr. Alexis Rodriguez, of the Planetary Science Institute, Tucson, Arizona, said: "It is positioned above catastrophic flood-eroded surfaces formed around 3.4 billion years ago."

At the time Mars was being bombarded with space rocks - suggesting "a marine impact
likely formed the crater," said Rodriguez.

The US team likened Pohl to the Chicxulub crater in the Gulf of Mexico where a city-sized asteroid crashed 66 million years ago - killing off the non-avian dinosaurs.

Rodriguez said: "The site's location along a highland-facing lobe aligned to erosional grooves supports a mega-tsunami origin based on its position above and below rocks previously dated to this time.

"Our mapping also shows Pohl's knobby rim regionally represents a broader history of mega-tsunami modification.

"Our findings allow that rocks and soil salts at the landing site are of marine origin."

Mars was once a waterworld with raging torrents bigger than the Nile. NASA rover Perseverance is currently drilling for signs of ancient life.

Pohl is about 500 miles northeast of where Viking 1 Lander (V1L) touched down in 1976 - near the terminus of an enormous flood channel, Maja Valles.

Its cameras imaged a boulder-strewn surface of elusive origin - which could be traced back to the mega-tsunami.

Rodriguez and colleagues identified numerous signs of the long-ago collision where an ocean likely once sat.

He said: "A Martian mega-tsunami may have been caused by an asteroid collision similar to the Chicxulub impact - which contributed to the mass extinction of all non-avian dinosaurs on Earth 66 million years ago – in a shallow ocean region."

Previous research has proposed that an asteroid or comet impact within an ocean in the Martian northern lowlands may have caused a mega-tsunami approximately 3.4 billion years ago.

The study in the journal Scientific Reports pinpoints the location of the resulting impact crater for the first time.

Rodriguez and colleagues analyzed maps of Mars' surface, created by combining images from previous missions to the planet.

Simulations showed craters with similar dimensions to Pohl were caused by either a six-mile wide asteroid encountering strong ground resistance – releasing 13 million megatons of TNT energy – or a two-mile wide one encountering weak ground resistance – releasing 0.5 million megatons.

Both formed craters measuring 65 miles in diameter and generated mega-tsunamis that reached nearly 1,000 miles from the center of the impact site.

Analysis of the mega-tsunami caused by the three-kilometer asteroid impact indicated that this tsunami may have measured up to approximately 250 meters tall on land.

The authors suggest that the aftermath of the proposed Pohl impact may have had similarities with the Chicxulub impact on Earth.

It occurred within a region 200 meters below sea level, generated a crater with a temporary diameter of 60 miles, and led to a mega-tsunami that was 200 meters high on land.