[meteorite-list] Very Bright Fireball Over Europe on Halloween Night

[Marco Langbroek]

> A lot of folks say it looked green to them, which means it may have been
> metallic;


It is a perpetuated misunderstanding that meteor colours are primarily due to 
their composition. It's a science myth inspired by High School Bunsen burner 
experiments that appears hard to kill.

While composition in some cases does have some influence on the colour, it is 
actually the composition of the atmosphere that is usually dominant for our 
perception of meteor colours.

That certainly is true for green colours. Meteor spectra show that meteors 
usually are very strong at the "forbidden" Oxygen line at 5577 Angstrom (557.7 
nm). This line is due to atmospheric Oxygen, the same atmospheric Oxygen 
exitation line also responsible for the green colours of Aurora.

So green meteor colours are likely atmospheric in origin and say little about 
the meteoroids' composition.

- Marco


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Dr Marco (asteroid 183294) Langbroek
Dutch Meteor Society (DMS)

e-mail: dms at marcolangbroek.nl
http://www.marcolangbroek.nl
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