[meteorite-list] Re: Entry Burn [was Lunar Burn]

[Marco Langbroek]

Ed,

Chris & me do not dispute that meteors can have different colours.

What we point out is that these colours do not necessarily reflect the meteoroid 
composition, such as was assumed earlier in the thread.

This is certainly the case for reported greenish colours, as we know from what 
meteor spectra exist that the Oxygen line at 558 nm (green), which is due to 
atmospheric Oxygen, often is a very prominent line in these spectra.

The contribution of gasses in the atmosphere will vary with respect to altitude, 
and energy release. This is very evident in photographs of persistent trains of 
meteors, e.g. the many shot by us and others during the Leonids the past decade. 
Quit often you see that the "early" (higher) part of this is green, while the 
later (lower) part of these is yellow-red.

- Marco

> Both entries were bright, and there
> was a distinct difference in spectra.
>
> I think this could go the way of the cold meteorites
> discussion, but fortunately in this case the color
> capabilities of automatic videotaping systems will
> probably resolve the question in the near future.
> 
> The one had a green cast to it, the other did not.  At
>  least that's how it looked to me.  I suppose for the
> time being maybe its best to leave it at that.
> 
> good hunting,
> Ed


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Dr Marco Langbroek
Dutch Meteor Society (DMS)

e-mail: meteorites at dmsweb.org
private website http://home.wanadoo.nl/marco.langbroek
DMS website http://www.dmsweb.org
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