Scientists discover the largest crater on Earth less than 100,000 years old

A crescent-shaped crater in Northeast China holds the record as the most impactful crater on Earth formed in the past 100,000 years.

According to a statement from NASA's Earth Observatory, before 2020, the only crater ever discovered in China was found in the coastal Xiuyan county of Liaoning province. Then, in July 2021, scientists confirmed that a geological structure in the lower Xing An An mountain range was formed by a space rock hitting Earth.

The Yilan crater in the Landsat satellite image.

The team published a description of the newly found crater that month in the journal Meteoritics and Planetary Science.

Accordingly, the Yilan crater is about 1.15 miles (1.85km) across and likely formed between 46,000 and 53,000 years ago, based on radiocarbon dating of coal and organic lake sediments from place. The researchers also collected samples of these sediments by extracting a drill from the center of the crater, Forbes reported.

The team found that, beneath more than 328 feet (100 meters) of the layered lake and marshy sediments, was a nearly 1,000-foot (320-meter) thick slab of calcined granite, a type of granite made up of many pieces of cohesive rock with each other into a matrix.

For example, fragments of rock show signs of having melted and recrystallized during the impact, when the granite heated rapidly and then cooled. Other fragments of the rock escaped this melting, and instead contained "shocked" quartz, which broke apart in a distinct pattern as the space rock fell.

The team also discovered teardrop-shaped pieces of glass and pieces of glass riddled with tiny holes created by air bubbles; Both of these features also indicate that an intense impact took place there, according to the NASA statement.

Global Times reported, part of the southern rim of the Yilan crater is lost, so the geological structure seen from above is crescent-shaped. Such crescent-shaped craters are relatively rare on Earth, Chen Ming, one of the paper's authors and a researcher from the Guangzhou Institute of Geochemistry, told the Global Times. In October 2021, the Landsat-8 satellite captured an impressive snapshot of the crater's northern rim, and scientists are now investigating how and when the southern rim disappeared, according to a statement from NASA.

The so-called Meteor Crater in Arizona previously held the record for the largest impact crater less than 100,000 years old; it is about 49,000 to 50,000 years old and is 0.75 miles (1.2km) in diameter. As reported by Forbes, the Xiuyan crater is 1.1 miles (1.8 km) across, but its age has yet to be determined.