(meteorobs) Meteoroid Streams and the Moon

[bob71741]

For those that are interested, I added the paper to the files section
as "Lunar Gravitational Focusing"; for those that do not have access
to the files section of Yahoo, the link to the paper is
http://www.springerlink.com/content/j1558234017p1043/

Best Regards
Bob

--- In meteorobs at yahoogroups.com, "Gural, Peter S."
<PETER.S.GURAL at ...> wrote:
>
>  
> All;
>  
> Regarding the question put forth by Chris et.al. - does the Moon
occasionally
> shield places on Earth from a stream? I actually published a paper
recently on this prospect for the Meteoroids 2007 conference entitled
"Lunar Gravitational Focusing of Meteoroid Streams and Sporadic
Sources" in "Advances in Meteoroid and Meteor Science" pp183-189. For
stream velocities of 34km/sec or less there is a focus point (and
associated flux enhancement) at the Earth-Moon distance if the Moon is
close to the radiant position. Higher than 34 km/sec and the flux
enhancmeent point moves beyond the Earth-Moon range, and an eclipse
occurs so to speak. The Geminids are 35 km/sec so are on the hairy
edge. The region of focus is very, very narrow - just a few thousand
km wide so the alignment must be nearly perfect for any flux
enhancement to occur. The journal article concerned itself with GEO
belt encounters but extrapolating to the Earth radius, the Moon's
alignment with the radiant position would need to be within one degree
to see any effect. This would appear as Geminid meteors moving along
non-Geminid radiant directions and a reduction in flux from normal
rates. I would have to work out the diameter of the eclipse region.
Just how close is the radiant to the Moon in this year's encounter ?
If more than a degree then the focusing/eclipse effect will be mostly
non-existant.
> 
> Cheers... Pete Gural
> 
> 
> 
> 
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