A Fiery Arrival
On March 8, 1976, at approximately 3:00 PM local time, a routine afternoon in Jilin Province was interrupted by a brilliant red fireball moving southwest across the sky. The object, a meteoroid entering Earth's atmosphere, generated several explosions and sonic booms before breaking into at least three distinct fireballs during its final descent. The subsequent meteorite shower scattered fragments over a 500-square-kilometer area. In total, about 4 metric tons of material were recovered, making it the largest documented stone meteorite fall in history.
The largest single fragment, officially named Jilin 1, weighs 1,770 kilograms (3,902 pounds) and is the heaviest individual stony meteorite ever recovered. This main mass slammed into the ground at high velocity, creating an impact pit 6.5 meters deep. Its impact registered as a magnitude 1.7 earthquake, providing scientists with rare data. Over 100 pieces were found in total, with the three largest fragments weighing 1,770 kg, 400 kg, and 123.5 kg. The main mass of Jilin 1 is now housed at the Jilin City Museum.
A Cosmic History in Stone
Analysis of the Jilin meteorite classifies it as an H5 ordinary chondrite, a common type of stony meteorite containing small, spherical mineral grains called chondrules. Its mineral composition includes olivine, pyroxene, and significant amounts of iron-nickel metal and troilite. Scientists determined the meteorite's history through cosmic ray exposure dating. As an object travels through space, it is bombarded by high-energy cosmic rays. These rays create specific radioactive isotopes, or radionuclides, within the rock at a known rate.
By measuring the concentration of cosmogenic nuclides like Aluminum-26, Cobalt-60, and Manganese-53, researchers can calculate how long the rock was exposed to space. This analysis revealed a two-stage exposure history for the Jilin meteorite. It spent about 10 million years near the surface of its parent asteroid before an impact event ejected it into its own solar orbit. It then traveled through space for approximately 400,000 to 2,000,000 years before its fiery encounter with Earth's atmosphere. The data also allowed scientists to reconstruct the meteoroid's pre-atmospheric size, estimating it was an almost spherical body with a radius of about 85 centimeters.