The object cut a bright streak across the night sky at around 2:30 a.m. local time, according to reports.
The IMO says the “extraterrestrial object” was likely a child-sized (1.5-metre) piece of space rock that caught fire in the Earth’s atmosphere.
Artist Kagaya Yutaka shared spectacular footage of the incident on Twitter shortly after it happened. The 13-second video shows the object going from a tiny mote of light into a ball of fire in the sky. He also reported hearing a “roar” from indoors.
Several witnesses also told the Japan Times that they heard a loud bang early in the morning as the suspected meteor passed. Police received several calls about the incident but there were no cases of damage, they told the Kyodo News outlet.
Nobuyuki Kawai, who works at the Akeno Observatory at the Toyko Institute of Technology, said he saw it on the observatory’s sensors.
Daichi Fujii, an astronomy expert in Hiratsuka City, shared another angle of the fireball. He said it’s extremely rare for fireballs to make a sound, and that it’s quite possible that part of the object may have hit the ground.
“It was a big fireball brighter than the full moon,” he wrote.
The explosion seemed to show up on sensors at two low-frequency monitoring stations 1,100 km and 2,300 km away, according to Lassina Zerbo, head of the Comprehensive Nuclear Test Ban Treaty Organization (CTBTO). The monitoring stations picked up the boom on their infrasound instruments.
The explosion had the force of about 150 tons of TNT, according to calculations by the IMO.
Most bits of space rock burn up in the Earth’s atmosphere as meteors or “shooting stars.” However, some large ones last long enough to create spectacles like the one in Tokyo.
About 44,000 kilograms of space rock fall to Earth each day, according to NASA.