The largest crater that has formed in the last 100,000 years on Earth has been found

Northeast China has hit a record-breaking crater as researchers say it is the largest impact crater on Earth in the last 100,000 years.

Prior to 2020, the only other impact crater ever discovered in China was found in Xiuyan County, Liaoning Province, according to a NASA Earth Observatory statement. Then, in July 2021, scientists confirmed that a geological structure in the Lesser Xing’an Mountains had formed as a result of a space rock hitting Earth. The team published a description of the newly discovered crater that month in the journal Meteoritics and Planetary Science.

The Yilan Crater is about 1.15 miles (1.85 kilometers) in diameter and probably formed about 46,000 to 53,000 years ago, based on dating from radioactive carbon and organic lake sediments from the site, according to a NASA statement. Researchers collected these sediment samples by extracting a nucleus from the center of the crater, Forbes reported.

According to the team, under more than 328 feet (100 meters) of multilevel lake and swamp sediments lay a slab of nearly 1,000 feet (320 m) of split granite, which is granite made up of many rock fragments cemented together in a matrix. This rock bears signs that it was hit by a meteorite.

For example, fragments of rock show signs of melting and recrystallization during impact, as the granite heated rapidly and then cooled. Other fragments of the rock escaped this melting process and instead contained “shocked” quartz that broke into a distinct pattern when the space rock collapsed, according to Forbes.

The team also uncovered tear-shaped glass fragments and pieces of glass pierced with tiny holes made from gas bubbles. Both of these characteristics also indicate that a high-intensity collision occurred there, according to a NASA statement.
Part of the southern edge of Yilan Crater is missing, so the geological structure looks crescent-shaped from above, the Global Times reported. Such crescent-shaped impact craters are relatively rare on Earth, Chen Ming, one of the authors of the article and a researcher at the Guangzhou Institute of Geochemistry, told the Global Times. In October 2021, the Landsat-8 satellite captured a stunning snapshot of the crater’s northern edge, and scientists are now investigating how and when the southern edge disappeared, according to a NASA statement.

The so-called meteorite 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 has a diameter of 0.75 miles (1.2 km). Xiuyan Crater, by comparison, is 1.1 miles (1.8 km) wide, but its age is unknown, Forbes reported.

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