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(meteorobs) Excerpts from "CCNet, 37/2000 - 22 March 2000"
The first item is particularly interesting. Curious this team should use earth
collected meteorite classes as the basis for classifying meteoroid debris: I
naively expect the bulk of meteoroid strikes in higher orbits would be from
cometary debris, which is completely unrepresented in earth-bound samples.
Clear skies,
Lew Gramer <owner-meteorobs@jovian.com>
------- Forwarded Message
From: Benny J Peiser <b.j.peiser@livjm.acdot uk>
To: cambridge-conference@livjm.acdot uk
Subject: CCNet, 22 March 2000
Date: Wed, 22 Mar 2000 13:06:28 -0500 (EST)
CCNet, 37/2000 - 22 March 2000
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[...]
(8) COLLECTION OF MICROMETEOROID REMNANTS FROM LOW EARTH ORBIT
G. A. Graham et al., OPEN UNIVERSITY
(9) IN-SITU DETECTION OF MICROMETEOROIDS AND ORBITAL DEBRIS
J.C. Mandeville et al., OFF NATL ETUD & RECH AEROSP
(10) A COMMENT ON GOLD DUST
Larry Klaes <lklaes@bbn.com>
=================================================================
(8) COLLECTION OF MICROMETEOROID REMNANTS FROM LOW EARTH ORBIT
G. A. Graham*), A.T. Kearsley, M.M. Grady, I.P. Wright,
J.A.M. McDonnell: The collection of micrometeoroid remnants from low
earth orbit. ADVANCES IN SPACE RESEARCH, 1999, Vol.25, No.2, pp.303-307
*) OPEN UNIVERSITY,PSRI,MILTON KEYNES MK7 6AA,BUCKS,ENGLAND
The solar array panel returned from the Hubble Space Telescope after
3.62 years of space exposure offered the opportunity to study
individual solar cells for hypervelocity impact damage and residue. A
detailed electron microscope investigation of impact craters (100-1000
mu m diameters) has identified that most are residue-rich and by
digitised x-ray elemental mapping and semi-quantitative micro-spot
analysis the original precursor composition of the impactor can almost
unambiguously be identified. The residues contain diverse elemental
compositions that can be associated with known meteorite mineralogies
and directly compared with interplanetary dust particles and
micrometeorites, possibly the most likely source object. The
observation of a magnesium-rich residue with (Mg+Fe) / Si ratio similar
to that of forsterite (end-member Mg-olivine identified in meteorites),
indicates that it is possible in favourable conditions to define
clearly the compositional nature of the impactor. The identification of
near-intact calcium-rich fragments, that are neither artefacts nor
contamination, indicates that volatile chemistries can survive
hypervelocity impacts in brittle glass substrates. The abundance of
micrometeoroid residues in the individual solar cells has highlighted
that valuable information can be retained from impact craters in
returned space hardware which are essentially not designed as a dust
collectors. (C) 1999 COSPAR. Published by Elsevier Science Ltd.
=================================================================
(9) IN-SITU DETECTION OF MICROMETEOROIDS AND ORBITAL DEBRIS
J.C. Mandeville*), C.R. Maag, C. Durin: In-situ detection of
micrometeoroids and orbital debris: The PIE experiment on MIR.
ADVANCES IN SPACE RESEARCH, 1999, Vol.25, No.2, pp.329-334
*) OFF NATL ETUD & RECH AEROSP,DESP,2 AV E BELIN,TOULOUSE,FRANCE
During the last few years, investigation of impact features found on
material retrieved after exposure to space for a long period of time,
in low earth orbits, has provided us with a great deal of data on the
particulate environment, either natural or man-made. The PIE detection
device presented here has been deployed outside the Kvant-2 module
attached to the Russian MIR station, between June 1996 and April 1997.
Part of the experiment uses a detection technique similar to the one
used in previous experiments flown on LDEF and MIR. Passive sensors are
composed primarly of stacked thin metal foils (gold and aluminium).
According to the size of the particles, they are either decelerated or
fragmented upon high velocity impact. The size of holes or impact
craters give information on the size or shape of the impacting
particles. Samples have been retrieved for laboratory analysis.
Comparison with data from LDEF, EuReCa, I-IST and previous experiments
on MIR provides insight in the long term evolution rf small particle
population and in the debris environment of a permanently manned
station. Some of the samples show evidence of secondary impact
cratering: an attempt is made to locate the origin of the primary
impact site. Some results about the possible origin of the impactors
are provided by the chemical identification of particle remnants inside
the craters. (C) 1999 COSPAR. Published by Elsevier Science Ltd.
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