The Great Chinese Fireball of December 22, 2020

TL;DR

This study analyzes a bright fireball over southeastern China, estimating its trajectory, orbit, and strewn field, suggesting an asteroidal origin and providing detailed impact data with implications for planetary defense.

Contribution

It provides the first detailed analysis of the December 2020 Chinese fireball, including trajectory, orbit, and strewn field estimations, based on satellite and observational data.

Findings

Fireball had a low inclination trajectory (~5°).

Explosion occurred at about 35.5 km altitude.

Strewn field estimated at 4000 km².

Abstract

On December 22, 2020 at about 23h 23m 33s UTC a very bright fireball was seen in the sky of south-eastern China. The fireball lasted for several seconds and ended with an atmospheric explosion that was detected by US surveillance satellites. According to CNEOS's data, the fireball moved with a mean speed of 13.6 km/s and exploded at an altitude of about 35.5 km (Lat. $31.9^{\circ}$ N; Long. $96.2^{\circ} $ E). In this paper we estimate the atmospheric trajectory, the heliocentric orbit and the strewn fields for different mass/section ratio of the fragments. The trajectory was about from north to south and with low inclination ($5^{\circ} \pm 2^{\circ}$) with respect to the local surface. The explosion height appear consistent with a fragmented rocky body and the heliocentric orbit supports an asteroidal origin. The probable strewn field extend between two points with coordinates ($+31.3^\circ$ N; $96.3^\circ$ E) and ($+30.3^\circ$ N; $96.5^\circ$ E), for a total area of about 4000 $\textrm{km}^2$. This large extension is a direct consequence of the low inclination of the trajectory. Given the unknown uncertainty of the CNEOS's data, these results should be taken with caution.