On November 29, 2020, 01:34 am (Japanese local time, which is Nov. 28, 16h 34min UT) a fireball ending with a terminal flash “as bright as the Full Moon” was observed from Western and Central Japan (Tokai, Kansai and Shikoku regions). According to some witnesses, it was accompanied with a “rumbling noise” and “skies went totally bright”. If the first point can’t be really checked, the second is clearly visible on the different videos of the event that were recorded from different parts of Japan.
As posted by Lassina Zerbo on Twitter could the extraterrestrial object that entered the Earth’s atmosphere also be measured by infrasound. A signature of a fireball was identified in the waveform of at least three stations of the International Monitoring System of the Comprehensive Nuclear-Test-Ban Treaty Organisation.
In the course of the NEMO (NEar real-time MOnitoring system) project, a preliminary source energy of the entering asteroid of about 10 t TNT was calculated by Esther Drolshagen and Theresa Ott. With an assumed density of 3000 kg/m3, several mass and size estimations can be calculated depending on atmospheric entry velocity:
* 15 km/s: size would be around 0.6 m diameter, with a mass of about 340 kg,
* 25 km/s: size would be around 0.4 m diameter, with a mass of about 100 kg,
* 35 km/s: size would be around 0.4 m diameter, with a mass of about 80 kg.