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Re: (meteorobs) Asher/McNaught Leonid model predictive value
In a message dated 8/29/99 2:29:04 PM Eastern Daylight Time,
marcolan@stad.dsldot nl writes:
<< Rob . . . I must say that you are right in your remark that
the historic fits of your model in a sense are proving the model's
predictive value (so I take back part of my reply I send in earlier). But
so apparently do for example William's and Wu's model, who also get good
historical fits but quite different results from it. >>
Marco -- you are correct on this point! As I also noted in the October 1998
WGN, the two chief studies available (at that time) based on the distribution
of particles with 55P/Tempel-Tuttle were from the teams of Brown and Jones
and Wu and Williams. Both teams carefully modeled the Leonid stream and
investigated its evolution on an assumption that most of the meteors observed
in 1965-66 were ejected from the comet at one of its previous three returns.
Both teams were very careful in having their respective models reasonably
account for the non-storm years of 1899 and 1933, as well as the storm year
of 1966. Yet, in the end we have DIAMETRICALLY OPPOSITE solutions:
Brown and Jones indicated that the Leonid showers from 1998 through 2000
would be strong, with the highest activity coming in 1999.
Wu and Williams' forecast was quite different, indicating that 1998 would be
either similar to 1899 or 1932, while their prediction for the 1999 Leonids
indicate that
" . . . few will be seen."
So indeed . . . even those who deal with the orbital dynamics of such things
can be at odds as well.
-- joe rao
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