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https://theconversation.com/city-killers-and-half-giraffes-how-many-scary-asteroids-really-go-past-earth-every-year-208838>
"Asteroids are chunks of rock left over from the formation of our Solar System.
Approximately half a billion asteroids with sizes greater than four metres in
diameter orbit the Sun, travelling through our Solar System at speeds up to
about 30 kilometres per second – about the same speed as Earth.
Asteroids are certainly good at capturing the public imagination. This follows
many Hollywood movies imagining the destruction they could cause if a big one
hits Earth.
Almost every week we see online headlines describing asteroids the size of a
“bus”, “truck”, “vending machine”, “half the size of a giraffe”, or indeed a
whole giraffe. We have also had headlines warning of “city killer”, “planet
killer” and “God of Chaos” asteroids.
Of course, the threats asteroids pose are real. Famously, about 65 million
years ago, life on Earth was brought to its knees by what was likely the impact
of a big asteroid, killing off most dinosaurs. Even a four-metre object (half a
giraffe, say) travelling at a relative speed of up to 60 kilometres per second
is going to pack a punch.
But beyond the media labels, what are the risks, by the numbers? How many
asteroids hit Earth and how many can we expect to zip past us?"
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
