April 27, 2020
Another Near Earth Asteroid has zoomed by while no one was looking on April 22nd. It may surprise the readers to learn that these things are so common that I only consider the ones that pass as close as the Moon to be of interest. This one was at 0.4 Lunar Distances or about 95,542 miles.
The culprit is 2020 HF5 – a small rock, as asteroids go – that is only 52 feet across. These encounters are listed at https://spaceweather.com/ – just scroll down a bit to find a table.
The rock in question is very much is roughly the same size as an asteroid that exploded over Челябинске in Russia on my 58th birthday. (Feb 15, 2013) . The heat of re-entry, combined with the tremendous air pressure of its hyper-sonic trajectory caused it to explode at 12 to 15 miles above the surface.
There was a Russian teacher – Yulia Karbysheva – about my age who, like me, had been trained in Civil Defense exercises in elementary school. They taught us what to do in a nuclear attack. When the meteor lit up the sky, she had her students hide under the desks – as she (and I) had been trained to do. When the asteroid exploded and the shock wave arrived, it shattered all the windows and sent shards of glass over the desks – with the students safely beneath same. After almost a half century, that training finally paid off – for the students. Unfortunately, she was so concerned with the fourth-graders that she remained standing and was seriously injured. In all, about 112 people were hospitalized, mostly cuts from flying glass. There were some cases of flash blindness and ultraviolet burns. Don’t look at the flash! I learned that instinctively as a welder.
Our more recent visitor was similar in size, but with only about 1/2 the relative velocity as that meteor and would have about the one fourth the explosive potential. About 117 kilotons – 9 Hiroshima bombs equivalent.
What’s that? Oh…it’s the town’s name – “Chelyabinsk”.