Did UFO cause a bright flash in the night sky over Kyiv on April 19, 2023? No, that's not true: The flash was a natural phenomenon known as a "superbolide", a term used by some astronomers when talking about an exceptionally bright meteor. A bright glow caused by this event was observed over Kyiv around 10pm local time, which led to various theories and false claims on social media.
An example of the claim that it was a UFO appeared in a video (archived here) where it was published by iiiigorrrrr on April 19, 2023. The hashtags read: #kyiv #ukraine #ufo #endoftheworld. It opened:
That's it, UFO is in Kyiv now. Dears, here is your 2023
This is what the post looked like on TikTok at the time of writing:
(Source: TikTok screenshot taken on Fri Apr 28 07:34:49 2023 UTC)
Shortly after the incident, Kyiv's military administration, Serhiy Popko, said on Telegram that an air raid alert was activated, but "air defence was not in operation". Popko suggested 'this phenomenon was the result of a NASA space satellite falling to Earth". NASA representative Rob Margetta denied to the BBC it was one of their satellites, saying it was "still in orbit".
Having studied the camera records at European Fireball Network (a project of the Astronomical Institute of the Czech Academy of Sciences operated in Slovakia in collaboration with the Astronomical Institute of the Slovak Academy of Sciences), the International Meteor Organization concluded the cause of the mysterious flash was a bright bolide (a large meteor burning up or exploding in the atmosphere). Kyiv videos show the middle and the end part of the bolide, whereas the beginning was captured in Hungary.