5 amazing impact craters on Earth that shed light on our planet’s history
The Earth is constantly being bombarded with space debris. Fortunately, most of it burns up when it enters our atmosphere, but some falls to the ground, leaving behind amazing impact craters.
Impact craters occur on every planetary body in our solar system, regardless of size. By studying impact craters and the meteorites that cause them, we can learn about the processes and geology that make up our entire solar system.
This list contains some of the most interesting impact craters on Earth:
1. Barringer Crater, USA
Barringer Crater, often referred to as meteorite crater, is located near Winslow, Arizona, USA, and was the first confirmed meteorite crater to result from an extraterrestrial impact.
The diameter of the crater is about a kilometer, and the age is about 50,000 years, which makes it relatively “young”. We have known about the crater since the late 19th century, but there is debate as to whether it was the result of an impact or associated with a nearby volcanic province.
It wasn’t until the 1960s, when high-pressure forms of quartz were found in the rocks, as well as meteorite fragments found nearby, that scientists were able to definitively say it was a meteorite impact.
The crater is a site of active research. It is well preserved, which makes it an excellent place to study the impact process. Since the early days of Apollo, Barringer Crater has also been used for astronaut training. This practice continues to this day as astronauts learn on the Artemis mission how to navigate terrain similar to what they would encounter on the Moon, as well as a bit of geology.
2. Chicxulub Crater, Mexico
Located in Mexico’s Yucatan Peninsula, this 180-kilometer-diameter crater is the second largest impact crater on Earth and dates back 66 million years ago, around the time of the extinction of the dinosaurs.
Geologists have been looking for mass extinctions recorded in rocks around the world for years. This did not happen until the discovery of iridium, an element more abundant in meteorites than on Earth, at the site of a meteorite impact.
The diameter of the object that fell to the ground was estimated at 10 kilometers, and it was moving at a speed of 20 kilometers per second. It’s about a 5 minute drive from Sydney to Los Angeles.
And it wasn’t just the dinosaurs that died out, as it is estimated that 75% of the plant and animal species on Earth died out as a result of this event.
The impact could be catastrophic immediately, with consequences for decades. There were strong tsunamis and forests were burning all over the world. Sunlight evaporated in ash and gases, perhaps for many years, leading to a global winter during which many species died.
3. Vredefort, South Africa
Crater impacts can be a source of economic resources. For example, an impact can result in the concentration of minerals present in situ prior to the formation of an impact crater, as is the case at the Vredefort structure in South Africa, where it is estimated that more than a third of the world’s gold was recovered from it.
The Vredefort impact structure is the largest confirmed impact crater on Earth and is about 2 billion years old. It was believed that the original crater had a diameter of up to 300 kilometers, but it collapsed significantly.
The impact unearthed some of the most ancient rocks on the planet. This is one of the very few places where you can see the complete geological record of a massive ancient third of Earth’s history, with rocks between 2.1 and 3.5 billion years old.
4. Tannoralla Crater (Gosses Bluff), Australia
Australia is home to 30 impact craters and these majestic geological structures are often considered sacred sites by local Aboriginal communities.
The Gosse Bluff impact crater is known to the people of West Arrente as “Tnorala”.
Today, Tanurala is 4.5 kilometers in diameter and 150 meters above the surrounding desert, but when it first formed 142 million years ago, its diameter was probably closer to 24 kilometers and has been eroded over time.
5. Nördlinger Rees, Germany
Nördlinger Rees Crater, also known as Rhys Crater, formed about 14 million years ago and has a diameter of about 24 km.
The city of Nördlingen is located inside the crater, south of the center. And if you climb the spire, you can see the edge of the crater.
Many of the buildings in the city, including the church, were built from the stones formed by the impact.
The crater contains layers of rocks and minerals that are better preserved than anywhere else on Earth. During the impact, the graphite was subjected to very high pressures and temperatures. This pressure turned the graphite into millions of tiny diamonds that dotted the buildings of the city.
The impact also affected the sandy layer of material near the surface, creating glassy green tektites. Tektites are glass formed when meteorites hit the Earth’s surface and can often be found hundreds or thousands of kilometers from their original impact site.