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Re: (meteorobs) Tunguska bolide & Beta taurid stream
In a message dated 99-06-25 15:43:48 EDT, you write:
Jure<<
From what I've read, the generally accepted diameter of a cometary Tunguska
body is between 100 and 200 meters.<<
I believe the current diameter that I've seen kicked around puts the tunguska
body roughly around 60 meters.
Jure>>If a nucleus of this size was active, the coma diameter would probably
be small and the surface brightness low. I don't know if I can link this to
the recen comet C/1998 K5 LINEAR, which was very near the Earth at the time
of discovery ( 0.3 A.U.) but was faint, around +14.5 magnitude (a question,
was this a mini-comet or a very unactive nucleus?). LINEAR was probably much
larger than Tunguska body, so the latter would have been even fainter. In
1908 probably noone would be able to pick it up, unless by chance someone saw
it with the largest telescopes, which were preoccupied with other projects.
>>
Although not scientific, I personally think that the Tunguska body was of
asteroidal material mainly because of the following:
It would seem that if there were a fair number of comets of such a small
size, there would be a lot more of them discovered by now using the various
larger telescopes that search for asteroids. If there were only one such
sized comet, it would seem to have been a very lucky shot to zero in on the
earth. Also,
There seems to be a lot more asteroidal objects zooming past the earth than
comets during any given period of time. Most comets essentially have "one
shot at us", whearas, the many Near earth asteroids being in shorter orbits
around the sun, have more frequent opportunities to have a collision with the
earth. The odds of it being asteroidal would seem greater based on this. Also,
There now seems to be an established track record of smaller "mini-tunguska
like explosions" from objects made up of asteroidal material to occur within
the earth's atmosphere roughly a dozen times/year.
Based on this mainly, I personally think that the 1908 tunguska object was
asteroidal in origin.
GeoZay
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