Beginning at around 2:45am on 20 January, Tweets were appearing with reports of an “explosion” and a glowing object falling from the sky. On the same day a video showing the meteor in high detail began to spread across the Japanese internet.
From the video we can easily see that this was no average meteor – this was a fireball.
Among the early reports were a few still images of the fireball. As rough as these were, they allowed trackers to get a good sense of where and how it fell.
Also this security footage provided a good sense of what witnesses experienced that night in Kanto.
Then as luck would have it, a car equipped with an event data recorder (camera) happened to be driving in the right place at the right time to get a crystal clear view of the fireball from start to its explosive finished.
Keep your eyes peeled at the 31 second mark.
From identifying the cars location while viewing the fireball in combination with all other data, fireball enthusiasts at the sky related phenomenon website SonotaCo Network Japan were able to paint a clear picture of the event.
A “fireball” is defined by the American Meteor Society as a meteor which glows brighter than -4 magnitude in the sky. This level of brightness is roughly equal to Venus’ when seen from Earth. The Sun’s magnitude is about -26.
According to SonotaCo this fireball had a magnitude of -10. This would likely classify it as a “bolide” which is loosely defined as having such a magnitude along with an explosion.
This fireball became visible “about 100km east of Chichibu City and touched down around the coastline in Mito City. It was falling at a 30°angle and at a speed of about 20km/s (44,700 mph).
Unfortunately, because it appears to have exploded over the water it might be hard finding any meteorites. However, if you happen to be hanging around the beach in Mito, you may want to be on the lookout for any unusual looking rocks.
▼ This data and many more sciencey charts can be seen at SonotaCo.
▼ The location of the event.