FYI,
The meteorites Leo and Marco V. are talking
about, are Pribram (6 april 1959) and Neuschwanstein (6 april 2002). Pribram
is a H5 chondrite, Neuschwanstein a E6 (E=Enstatite) chondrite. The Dutch
Glanerbrug meteorite (7 april 1990), an LL5, also has a quite similar orbit
(determined from visual observations). They might all three originate from one
'rubble pile' parent asteroid. A 'rubble pile' originates when after a
collision between two or more objects, fragments of these multiple
objects reassemble again into one body due to gravitational
binding.
Concerning the meteor aspect (as this is a
meteor observer's list): radiant positions are: alpha 192, delta +19
(Pribram); alpha 192, delta +17 (Neuschwanstein); alpha 202, delta +49
(Glanerbrug). Velocities 21-23 km/s. For those interested in the details, see
paper by Spurny et al. in Nature 8 May 2003, and my paper in 'Radiant' (J.
DMS) of September 2001. Note that the radiant area has a diameter of some
30 degrees, stretching from Coma Berenices into Canes Venatici.
What is much more 'problematic' than the
difference in chemical classifications, is the CRE (Cosmic Ray Exposure) ages
for these objects. They suggest they orbited the sun as small (i.e. meteorite
sized) objects for tens of millions of years, which seems at odds with an
intact stream. This paradox has not yet been satisfactorily solved.
Personally, I think it could mean that CRE ages are not what people think they
are.
I think that Neuschwanstein and Pribram have
been discussed on this list a year ago following the Neuschwanstein fireball
and subsequent meteorite recovery a few months later. So Leo and Marco V.
might want to check up the list archives.
- Marco Langbroek
----- Original Message -----
Sent: Monday, May 26, 2003 7:50 AM
Subject: Re: (meteorobs) Fwd: Meteor's
family poses puzzle - Intriguing!
----- Original Message -----
Sent: Sunday, May 25, 2003 8:32
PM
Subject: Re: (meteorobs) Fwd: Meteor's
family poses puzzle - Intriguing!
At 19:56 25/05/03 -0300, you wrote:
Hi Marco,
I should have been more specific,sorry -
basically,meteorites were recovered from both events,and both fireballs were
captured on multiple cameras and their orbits determined as being the
same(ie they must have come from the same parent body),but,the recovered
meteorites were found to be of different composition when
analyzed,suggesting that they came from different parent bodies,which
contradicts the photographic evidence!
________________________
Hi Leo,
Two family bodies having the same orbit is still very intriguing
to me. Luck that you have evidences of them in photos. But since you added
that "after they were analysed ...they come from different parents body
(composition...)". So what may missing is that the photos were taken from
two differents bolides: one in 59 and the other in 2002. No? Admiting that
mags. as determinats as well as the size, the time, the train and the years,
why not consider them as two DIFFERENT parallels comets that joined
casually(!) in the same gravitational orbit falling over the earth?
Finally after being, captured as meteorites after their journey over
the Sun? And again, after concluding their long path reaching the
ground. So two different fireballs that come and go, and both have
fragmented. That's not easy to admit, but it's plausible!
If it's not this I am still in needing to taking a read on
the link forwarded. Again nothing that can be related in terms of comets can
necessarily be determined as that they are really from the same body. At
least on the way I understand comets and asteroids. Even considering
that they (all) could come from Vanderbilt belt.
Is true that in many light years ago part of comets showers are coming
and entering into our atmosphere. Why (again) not considering that this
particules (meteorites) are an integral element of an only one
high bolide that have crashed in many billion years ago and that just now
came in. After competent labs analyses -, scientifically is
evident that that they may belong from an only one parent body
meteorite. You say. I add: Route, orbits, paths and journeys come from
well-know asteroids (old planets) gravitational.
Moreover, even knowing that it is not too easy too admit this, I
myself am firmilly aware that this could be a plausible thesis to add
some light on the subject you are investigating. There's no other way to
assure you that these bolides (59) and the fireball (02) are from the same
asteroid than this one. Now I will take a serious reading on your link.
Please, do not wait great expectations. I'm still in beliefs that both could
be two parallels meteors, and/or an only one integral comet from a big
blow-up in the past orbiting that came over our atmosphere.
Well, in my opinion most brilliant
objects in cosmos, such as fireballs, follow an orbit. Ins't that
impossible the the first (1959), didn't fragment tottally. Very probably
that part of that bolide kept on its journey untill it ended up
again over the the skies of Central Europe (2002) in the form of a
shower.
Ruled out since the composition differed in both the recovered
meteorites.
______________
I tried to explain about it above.
______________
_________
Marco
Clear skies