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Re: (meteorobs) size/? length of typical meteor
----- Original Message -----
From: <chiayk@popdot singnet.com.sg>
Subject: (meteorobs) size/? length of typical meteor
> Hi folks:
>
> What is the size of a typical bright visual meteor? Say take the
> example of an brighter than -2 Leonids.
> Since the theory goes that the green-yellow-orange-red correspond to
> result from ionization with element/ions from diff atmo height, can I
> infer that they are at least 50+ Km long? (what about the width of the
> column ?)
>
>
> rgds
> ykchia
>
In answer to the above, shower meteors such as the Leonids and Perseids
are of cometary origin and as a rule are not solid objects but are a loose
aggregate of dust particles. In other words, dust balls. The size of a -2
magnitude dust ball is probably around a cm to a few cm. According to
studies by Millman and others, they generally become visible at a height of
around 100 kms and burn out at around 80 kms. Higher velocity Leonids
become visible at slightly greater heights. Path lengths of course vary but
I would expect lengths of 10 kms to probably 30 kms or so. The ionized
column is a cylinder around a meter in diameter. This cylinder expands as
time passes to possibly 1 km in diameter. If you want to read more about
this see:
Journal of the Royal Astronomical Society of Canada (JRASC) Vol 65, Number
1, February 1971, Meteor News, Heights of Meteor Spectra by PM Millman,
p.37-p.38.
also
Physics of Meteor Flight in the Atmosphere - Ernst J. Opik (1958)
and
Meteor Science and Engineering - D.W.R. McKinley (1961)
Ed Majden - AMS Meteor Spectroscopy Project Coordinator
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