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Re: (meteorobs) RE: Leonid max?
>That thread was actually in preparation for another question I was wondering
>about the Leonids: is there enough data from the 1933 and 1966 storms,
>
>Lew
Actually, Lew, the Leonids did not produce an impressive display in 1933,
or 1899 for that matter. This is what makes the whole prediction a little
uncertain.
We know that great displays occurred in 1799, 1833, 1866, and 1966, and
there are numerous accounts from years prior to this as well. Donald
Yeomans (JPL) has extensively examined the Leonids stream and has produced
a model of the cloud of meteoric debris surrounding the parent comet,
Tempel-Tuttle, by noting where Earth crossed the comet's orbit during years
of great, normal, and negligible activity. He has noted that the lack of
displays in 1899 and 1933 were due to perturbations by other planets having
increased the closest distance between Earth and the comet's orbit. The
1966 display happened because perturbations had caused that same distance
to decrease.
It is obvious that the Leonids are increasing in intensity as the comet
draws closer to us each year, but how strong the displays will be when the
comet is closest is still a matter of debate. First, the comet passes
perihelion on February 28, 1998. What this means for us is that Earth will
pass closest to the comet's orbit in 1997 and 1998 at times when we are
rather far from the comet. This was not the case in 1966. Second, the
regions of the meteoric dust cloud that Earth will encounter have not been
encountered before.
Yeomans has said a very strong display is likely, with the best years being
1997 to 1999 (the cloud extends behind the comet quite a ways), but
cautions that an irregular dust distribution within the cloud could bring
either bad or good surprises.
Stay tuned on this one!
Gary