[meteorite-list] Frequent Fireballs
Ron Baalke
baalke at zagami.jpl.nasa.gov
Mon Dec 4 00:58:55 EST 2006
http://spaceweather.com/
Frequent Fireballs
spaceweathter.com
December 3, 2006
HOW MANY FIREBALLS? Have you ever stepped outside after dinner
to walk the dog--just in time to see a bright fireball streak
across the sky? It makes you wonder, how often does that happen?
Pretty often, according to astronomer Bill Cooke of the Marshall
Space Flight Center. Using a computer model of Earth's meteoroid
environment, he made this plot showing the global number of
fireballs per day vs. the brightness of the fireball:
[Plot]
According to his calculations, fireballs as bright as Venus
appear somewhere on Earth more than 100 times daily. Fireballs
as bright as a quarter Moon occur once every ten days,
approximately, and fireballs as bright as a full Moon once
every five months.
The vast majority are never noticed. About 70% of all fireballs
streak over uninhabited ocean. Half appear during the day,
invisible in sunny skies. Many are missed, however, simply
because no one bothers to look up. So grab a leash and a dog
(optional), and head outside. The chance of a fireball is
better than you think.
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