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Re: (meteorobs) Re: fireball + METEOR
In a message dated 99-07-09 19:41:29 EDT, you write:
lunsford<<
Norman is correct when he states that "the meteor is far faster than any
meteor I have ever seen, and I have recorded nearly 89000 of them". The
fastest angular velocity possible is 38 degrees per second meaning that
a meteor can travel 90 degrees in no less than 2.4 seconds. Rarely does
a meteor travel at this velocity as even the swift Leonids have an
average angular velocity closer to 20 degrees per second. A velocity
approaching the maximum value can only be achieved if the meteor lies 90
degrees from the radiant and close to the zenith. I also agree with him
that it is odd for someone to overestimate the velocity as nearly
everyone tends to underestimate this factor.
>>
From a 1948-1950 Canadian Radio Survey, it has been learned that less than 1
percent of all meteors were traveling faster than the established 72 km/s
solar speed limit. Of these that were traveling at apparent hyperbolic
speeds, none were traveling faster than 80 km/s. As the survey noted, this
excessive solar speed is within the realms of being measurement errors. But
in recent years, additional research has been done that indicates the
Canadian survey was relatively accurate. The Christchurch (New Zealand)
meteor radar AMOR (Advanced Meteor Orbit Radar) has also yielded about 1 % of
meteoroids haveing an atmospheric speed in excess of 100 km/s. In addition,
the Ulysses space probe dust detector has in 1994, discovered interstellar
grains in the outer solar system at about 5 AU, having hyperbolic
trajectories. This means it's traveling too fast to stay in orbit around the
sun.
GeoZay
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