VonMark the heels,Australian Nuclear Science and Technology Organization
I think all the craters are cool, so I'll start with that. I am very biased.
Impact craters occur on all planetary bodies in ourssolar system, Size does not matter. By studying impact craters and the meteorites that create them, we can learn about the processes and geology that shape our entire solar system.
This list includes some of my favorite impact craters here on Earth.
1. Meteor crater, Arizona, USA
The one who started it all.
Barringer Crater (often called Meteor Crater) is located near the town of Winslow on Route 66 in Arizona. It was the first crater confirmed to be from an extraterrestrial impact.
The meteor crater is about 1 km in diameter and about 50,000 years old, making it relatively "young". We have known about the crater since the late 1800s, but there has been debate as to whether it was an impact or was associated with the nearby volcanic province.
It wasn't until the 1960s that scientists identified high pressurequartz shapeson the rocks. Combined with meteorite fragments found nearby, scientists were able to conclusively say it was onemeteorite impact.
The crater is an active research site. It is well preserved, making it an excellent place to learn more about the impact cratering process. Meteor Crater has been a place for astronauts to train since the early days of Apollo. The practice continues today, withAstronaut ArtemisLearning to navigate terrain like you would find on the lunar surface plus a little bit of geology.
Today you can visit the crater (the gift shop is excellent!) and take a tour of the crater rim. It's a great addition to any trip to the Grand Canyon.
2. Chicxulub, Yucatan, Mexico
The Killer Dinosaur!
Possibly the most famous meteorite impact on Earth is the one that largely buried the Chicxulub impact structure in Mexico's Yucatan Peninsula. This 111-mile (180 km) diameter crater is the second largest on Earth. Scientists date it66 million years ago, coinciding with the extinction of the dinosaurs.
For years, geologists have been searching rocks around the world for a mass extinction event. It wasn't until the discovery ofirídio, an element much more common in meteorites than on Earth, that the parts collapsed.
Scientists estimate that the object that struck Earth would be 6 miles (10 km) in diameter and traveling at a speed of 12 miles per second (20 km/s). Driving from Sydney to Los Angeles takes approximately 5 minutes.
Not only the dinosaurs are extinct. As a result of this event, about 75% of the world's plant and animal species became extinct.
The effects would have been catastrophic immediately, with decades of aftermath. There were huge tsunamis and burned forests all over the world. Ash and gases could have snuffed out sunlight for years, triggering a global winter that killed many other species.
Eventually, however, the crater system became onethriving deep biosphereas the planet repopulated at the end of that long winter.
3. Vredefort, South Africa
The great.
Impact craters can be a source of economic resources. For example, the impact can concentrate pre-existing metals during cratering. It can also uncover buried sediment that would otherwise not be near the surface.
The latter is the case with the Vredefort structure in South Africa. More than a third of the world's gold comes from here.
The Vredefort impact structure is the largest confirmed crater on Earth and is approx2 billion years. The original crater was up to 300 km in diameter but has since eroded.
The impact exposed some of the oldest rocks on earth. It's one of the few places where you can see a complete geological record of a third of the Earth's history. Rocks here are between 2.1 and 3.5 billion years old.
When most people think of an impact crater, they think of a roughly circular depression like Meteor Crater. But craters can have different shapes and properties. Vredefort has the complex shape of an impact basin with multiple rings. These pools form in large impacts. You can also see them on other bodies in the solar system.happy Easteron the moon is an example.
4. Tnorala Crater (Gosses Bluff), Northern Territory, Australia
dream stories.
Australia is home to the world's oldest continuously living culture, with evidence of people living on the continent since at least 200065,000 years. It is also home to 30 impact craters, and these imposing geological structures are often sacred sites for local indigenous communities.
The Bluff de Gosse impact crater is known asTnoralaby the western Arrernte people. From themdream storiesFrom the time of formation, tell the resulting crater:
… when a group of women danced in heaven while theMilky Way. In this dance, a mother laid her baby on its side in her wooden stroller. The transporter tumbled over the edge of the dance floor and landed on the floor where it became the circular rock formation of Tnorala.
Today, Tnorala is 4.5 km in diameter and rises 150 m above the surrounding desert. But when it formed 142 million years ago, it was probably about 15 miles in diameter and has eroded over time.
Several other craters in Australia are associated with song and dream stories. one is theHenbury-Kraterfeld, which is 75 miles (120 km) southeast of Gosses Bluff. It is one of the few impact events that have been observed by humans. This meteorite landed in what is now central Australia 4,700 years ago.
5. Nordlinger Ries, Germany
diamonds and precious stones.
The Nördlinger Ries, also just called the Ries crater, was one that I was lucky enough to visit. It was formed about 14 million years ago and is approx15 miles (24 km)In diameter. The town of Nördlingen is in the crater, just south of the center. If you climb the church tower you can see the top of the crater rim.
This was the second crater proven to have been caused by the impactsame teamwho examined the meteor crater.
Again identifying a form of high-pressure quartz -coexistHe held the key. Previously, scientists had found this mineral naturally only in rocks formed deep within the Earth's interior or during nuclear test explosions. Neither was detectable in Nördlingen, so the cohesive must have formed during an impact.
Residents built many buildings in the city, including the church, from rocks formed in the impact. These include a breccia rock (which literally means broken into angular fragments) called suevite. This particular suevite is special because the rock contained a layer of graphite prior to impact in this part of Bavaria.
During the impact, the graphite experienced high pressures and temperatures. This transformed the graphite into millions of microdiamonds that exist in the city's buildings.
The impact also blasted into a sandy layer of material near the surface, creating a glassy green.Tectitas. Tektites are high-impact glass formed from material thrown high into the atmosphere. They can often be found hundreds or thousands of kilometers from the original impact site.
In this case, scientists found them in the Czech Republic near the Vltava River. So your name:Moldova. Unlike diamonds in reams, moldavite occurs in specimens large enough for people to use as a semi-precious stone in jewelry.
Find more craters
The five impact craters mentioned above are diverse and unique. None of them exhausted all the scientific questions we could ask.
Excitingly, there are even more craters than we could find on Earth. As satellite imagery data sets become available with even higher resolutions, we can identify more potential impact structures in remote areas. Field geologists could explore them, looking for structure and chemical evidence of an impact.
Each crater - no matter how old or obscure - stands ready to teach us something new about our planet, our solar system and the geological processes that shape it.
Mark the heels, Senior Beamline Scientist - Powder Diffraction,Australian Nuclear Science and Technology Organization
This article is republished byThe conversationunder a Creative Commons license. read thisoriginal article.
In short, we've highlighted five impact craters on Earth that are giving scientists a glimpse into our planet's wild and violent history.
