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Re: Fireball brightness estimates



Hi Lew,

I saw your remarks on estimating the brightness of fireball events and I agree with you that it 
is very difficult. It is my personal experience that estimating the lighting of the surrounding is a 
more reliable estimate of fireball brightness than trying to comparing the actual brightness of 
the meteor to that of the Full Moon. The reason for this is problably that very bright fireballs 
are often rather close to the observer (e.g. 50 km range) which causes the meteor to get real 
angular dimensions instead of being a point source.

I suggest the following scale:

-6 discernible lighting of the surrounding (or ground shadows as Lew suggested)
-9 clear lighting of the surrounding
-12 enormous lighting of the surrounding, as with the Full Moon
-15 I have never witnessed this one and I guess you will recognize its brightness when you 
see it....

There is only one problem: when you happen to see the fireball you will not turn away your 
view to look at the surroundings. If you observe in a group normally one or two observers will 
have missed the fireball. You better believe them when it comes to brightness estimates!

Marc

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Marc de Lignie
Prins Hendrikplein 42                        Tel. +31 (70) 320 5673
NL-2264 SN  Leidschendam            Fax. +31 (70) 332 6477
The Netherlands                                E-mail: mcdelign@pidot net

Predicted progress always fails. Real progress is all the small
steps you realize to have made when looking back in time.
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