If you’re curious about the amazing find in geology, here’s the scoop:
- Impact craters often disappear from the Earth’s geological history due to erosion and shifting tectonics.
- Chinese scientists have discovered a remarkable impact crater created in our current epoch, measuring an impressive 900 meters — three times larger than the previous record holder!
- This impact event likely occurred fewer than 10,000 years ago, sparked by a 30-meter wide asteroid traveling at about 45,000 miles per hour.
When you look at impact craters, places like Mars or Mercury show off their scars from billions of years of cosmic chaos, while Earth keeps its history a bit more secretive thanks to erosion and busy tectonic plates. Sure, some ancient impacts, like our encounter with the protoplanet Theia or the infamous Chicxulub that wiped out the dinosaurs, are still worth studying, but the lesser impacts from Earth’s early days have mostly vanished.
Nowadays, our atmosphere tends to burn up a lot of incoming threats before they wreak havoc on the surface. Still, there are serious impacts recorded from the Holocene period. The largest prior to this discovery was the 300-meter Macha crater in Russia — up until now. A new study led by a team from China has revealed a striking impact crater located in Guangdong Province, which is an astonishing 900 meters wide!
Ming Chen, the lead author from the Center for High Pressure Science and Technology Advanced Research in Shanghai, remarked, “This discovery is evidence that small extraterrestrial impacts on Earth in the Holocene epoch were far more significant than previously understood.” In a recent statement, he emphasized its significance.
This crater was found in an area renowned for its heavy rains and high humidity, not typically the best conditions for preserving geological features. However, the crater is quite clear and unmistakably shows signs of a meteorite impact rather than a comet strike (which would create a larger crater).
Geologists identify impact craters by looking for characteristics called “planar deformation features” within quartz grains, showing signs of extraordinary pressure from such events.
As Chen elaborated in another statement, “The development of planar deformation in quartz can only happen from the intense shockwaves generated by celestial body impacts, requiring pressures from 10 to 35 gigapascals — no earthly process can replicate that kind of shock.”
The researchers theorize that around 10,000 years ago, a 30-meter asteroid barreled into a granite hillside, traveling at a stunning 20 kilometers per second (approximately 45,000 miles per hour). This collision sent granite debris flying, which later settled back around the crater’s edge. On the northern side, the impact even penetrated the underlying granite bedrock.
While more precise dating is necessary, by measuring the granite’s chemical weathering rate in the rainy hills of Guangdong — about 0.038mm per year — and analyzing the fragment sizes found at the site, scientists believe this colossal event likely took place during the early to mid-Holocene (less than 10,000 years ago).
The Jinlin impact crater is now part of a select group of confirmed impact sites on Earth, totaling around 200 — a fraction compared to the thousands of times Earth has been struck over its 4.6 billion years. Each of these impacts has played a role in shaping the planet we all call home.
