On 23.12.2020 at 07:23 am local time (22.12.2020, 23h23 UT) a bright fireball could be seen flying over Southern China, Nanqiang County. Since it was the Day before Christmas Eve, could it have been Santa practicing his delivery route?
Apparently, it was something even more spectacular, a piece of extraterrestrial material. These fireballs are caused by asteroids entering the Earth atmosphere at a high velocity and lighting up the atmosphere around it.
However, this piece was especially energetic, with the equivalent of 9.5 kt TNT according to CNEOS. They found a velocity of the entering object of about 13.6 km/s.
This explosion was so high in energy that it was even picked up by the infrasound arrays of the CTBTO, designed to capture nuclear explosions.
#CTBTO #IMS network detections by stations I34MN Mongoli🇲🇳, I45RU #Russia🇷🇺, I60US United States🇺🇸 & I39PW #Palau🇵🇼 of large fireball🔥over South #China🇨🇳. Event occurred on 22/12/2020 at 23:23 UTC : Nothing goes undetected ! pic.twitter.com/RSVwp0mn48
— Lassina Zerbo (@SinaZerbo) December 24, 2020
With this method, the energy seems to have been much lower. Since three stations recorded the event, a preliminary energy of 0.5 kt TNT could be determined. This would mean that the asteroid that came down was 3 m in size. This would be a lot smaller than what CNEO’s optical method detected and calculated from satellite observations.
The signal of the explosion is clearly visible in the waveform of the station I34MN.