[meteorite-list] Farmington

From: almitt <almitt_at_meteoritecentral.com>
Date: Thu Apr 22 09:48:14 2004
Message-ID: <3BDD25DA.639D06DE_at_kconline.com>

You wrote:

>>I've heard before that Farmington was probably part of a meteoroid stream
(which was the main reason I purchased a slice of it for my collection) that
was observed to have impacted the moon. The fall date of this meteorite was
June 28, 1890. If I'm not mistaken this would make it part of the Taurid
stream. <<

Hi Rhett,

Not everyone is an astronomer on this list so I will try to explain what I know without going too far out on a limb. Meteor shower streams like
the Taurids are from cometary orbits and the suspected comet is Encke's Comet. The Taurids were one of the best meteor showers about a thousand
years ago. Pretty spread out these days. In most cases the debris is very small particles behind the comet which strike our atmosphere and
make the show when the Earth intersects the orbit of the debris stream. This shouldn't be confused with meteoroid streams, larger chunks from
collisions (in the asteroid belt) being perpetrated by Jupiter's strong gravity of influence into a longer and longer orbit until we can have
one (perhaps more) come down as a fireball and potential meteorite if it hits the ground.

The story doesn't end there!! It is thought that sometimes comets can be affected by planetary gravity influence (Jupiter is a good culprit)
and such comets can end up in shorter orbits (not going all the way out well past Pluto's orbit and beyond, some that do resemble asteroidal
material and after a few hundred passes past the sun wear out their icy layers and resemble asteroids themselves more. We also see some
asteroids gas a little bit (lets keep it clean folks) and perhaps these were once remnants of comets. Perhaps the difference isn't a lot. In
time we will see what formed in the layer between Jupiter and Mars and what might be captured comets. It might be possible that we have
cometary meteorites but so far no evidence is in existence to my knowledge of such a fall being recorded to such a parent body.

I also remember somewhere where the Farmington meteoroid stream (belongs to one of the crossing asteroid families I can't remember now) was
watched to see if any resulting impacts occurred on the moon. Perhaps someone can spell this out better.

I'll leave the Tunguska event to someone else. Good night!

--AL
Received on Mon 29 Oct 2001 04:48:11 AM PST