Australian Scientists believe to have identified the world’s oldest known meteorite impact crater. It is being understood that this finding could reshape the understanding of Earth’s history and the origins of life. The crater, discovered in the remote North Pole dome region in northwestern Australia, is estimated to be 3.47 billion years old. It is presumed to be more than a billion years older than any previously known impact site.
An impact crater is formed when an object, like an asteroid or meteorite, crashes into the surface of a larger solid object like a planet, earth, or a moon. To form a true impact crater, this object needs to be traveling extremely fast—many thousands of miles per hour!
According to a news agency, researchers from Curtin University said their discovery “significantly challenged previous assumptions about our planet’s ancient history.” Professor Tim Johnson, a co-lead of the study, highlighted its importance, stating, “Before our discovery, the oldest impact crater was 2.2 billion years old, so this is by far the oldest known crater ever found on Earth.”
The crater, named the North Pole Crater, was likely formed by a meteorite striking Earth at more than 36,000 kilometers per hour, creating an impact site over 100 kilometers wide. The collision may have sent debris flying across the planet, with molten droplets possibly landing as far away as South Africa.
The discovery also sheds new light on how meteorites influenced early Earth. Professor Chris Kirkland, another lead researcher, explained that impact craters could have created environments suitable for microbial life.
“Uncovering this impact and finding more from the same time period could explain a lot about how life may have got started, as impact craters created environments friendly to microbial life, such as hot water pools.”
The researchers discovered key geological evidence at the site, including “shatter cones,” distinctive rock formations that form only under extreme pressure from meteorite impacts.
“They’re these beautiful, delicate little structures that look a little bit like an inverted badminton shuttlecock with the top knocked off,” Johnson described. The presence of these formations is considered unambiguous proof of an impact.
The study, published in the scientific journal Nature Communications, also links the discovery to Earth’s crust formation. The tremendous energy from the meteorite strike may have played a role in shaping the planet’s surface. “It radically refines our understanding of crust formation,” Kirkland said, suggesting similar discoveries could further explain how Earth evolved billions of years ago.
However, some scientists remain cautious. According to Australian news outlet, planetary scientist Marc Norman from the Australian National University acknowledged the discovery as “compelling” but noted that more evidence is needed to determine the crater’s exact size and its broader role in Earth’s history.
“While the discovery of this ancient impact crater is interesting, it doesn’t really advance our understanding of how impacts might have influenced how Earth formed and evolved over billions of years,” Norman said.
The researchers plan to conduct further studies in the Pilbara region to search for more ancient craters. “We’ll do the various horrific things we do to rocks … in our labs to analyse them for all sorts of elements and isotopes and microstructures,” Johnson said.
While some past claims of ancient craters, such as those in Greenland, have been inconclusive, the new discovery is backed by strong geological evidence.
In fact, when a solid object crashes into something at these super-fast speeds, it forms a crater regardless of how hard or tough it is. It immediately vaporizes and creates enormous shockwaves through the ground that melt and recrystallize rock. All that’s left is a big circular hole in the ground and some seriously mangled rocks!
Some of the other meteor craters are:
Meteor Crater (also known as Barringer Crater) in Arizona was the first crater discovered to be formed by an extraterrestrial impact. It formed 50,000 years ago from a meteorite that may have been up to about 150 feet wide traveling more than 28,000 mph.
Tycho Crater, in the moon’s southern hemisphere, is believed to be about 108 million years old—young, by moon standards.
Vredefort crater in South Africa is the largest known impact crater on Earth—almost 200 miles across! At over 2 billion years old, it is also one of the oldest. Because of erosion over this long time period, the crater is a bit difficult to see.
An asteroid or meteor is more likely to hit Earth because Earth is a lot bigger than the Moon, giving a meteoroid more area to hit! But we can see many thousands of craters on the Moon and we only know of about 180 on Earth!
The truth is both the Earth and the Moon have been hit many, many times throughout their long 4.5 billion years’ history.
The main difference between the two-Earth & Moon- surfaces is that Earth has processes that can erase almost all evidence of past impacts. The Moon does not. Pretty much any tiny dent made on the Moon’s surface is going to stay there.
Three processes help Earth keep its surface crater free. The first is called erosion. Earth has weather, water, and plants. These act together to break apart and wear down the ground. Eventually erosion can break a crater down to virtually nothing.
The Moon has almost no erosion because it has no atmosphere. That means it has no wind, it has no weather, and it certainly has no plants. Almost nothing can remove marks on its surface once they are made. The dusty footsteps of astronauts who once walked on the Moon are still there today, and they aren’t going anywhere anytime soon.
The second thing is something called tectonics. Tectonics are processes that cause our planet’s surface to form new rocks, get rid of old rocks, and shift around over millions of years.
Because of tectonics, the surface of Earth is recycled many times throughout its long history. As a result, very few rocks on Earth are as old as the rocks on the Moon. The Moon has not had tectonics for billions of years. That’s a lot more time for craters to form and stay put.
The third thing is volcanism. Volcanic flows can cover up impact craters. This is a major way impact craters get covered up elsewhere in our solar system, but it is less important than the recycling of crust here on Earth. The Moon once had large volcanic flows way in the past that did cover up many of the bigger earlier impacts, but it has been without volcanism for around three billion years.
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