[meteorite-list] RE: Measuring Density

From: Herd, Richard <herd_at_meteoritecentral.com>
Date: Thu Apr 22 10:23:51 2004
Message-ID: <3E3C279AF3F9D411BAA00002A529150E501AC5_at_s0-ott-x10.nrn.nrcan.gc.ca>

Dear List:

My colleagues and I have a (so far expensive) means of determining the
density of any object without immersing it in anything. In a poster
presented at last week's 34th Lunar and Planetary Science Conference in
Houston, we reported that the first recovered piece of the St-Robert
meteorite has a volume of .69 L. It's mass is 2290 grams, yielding a =
density
of about 3.3 gm/cc. The volume was calculated by combining Point Cloud =
data
from a laser camera to make a closed wireframe model: essentially =
scanning
all surfaces of the object and combining the results to define the =
volume in
3D space occupied by the object.

See the (Herd et al.) abstract at:

ftp://www.lpi.usra.edu/pub/outgoing/lpsc2003/full69.pdf

The .69 L result was not in the abstract but it was in the final poster =
text
and I spoke with Guy Consolmagno and others to point out to them what =
we had
managed.

Ideally you do not want to immerse meteorites in anything, especially =
water.
They have a porosity often derived from their stressful entry through =
the
atmosphere. They are full of fine cracks from this and may also have
primary porosity.

RKH
------------------------------------------------------------------------=

Dr. Richard K. Herd,
Curator / Conservateur,
National Collections / Collections nationales,
Geological Survey of Canada / Commission g=E9ologique du Canada,
Natural Resources Canada / Ressources naturelles Canada,
601 Booth Street / 601, rue Booth
Ottawa, Ontario K1A 0E8 / Ottawa (Ontario) K1A 0E8
Government of Canada / Gouvernement du Canada

Tel / T=E9l: (613) 992-4042; 998-0381
Res / R=E9s: (613) 526-5050
Fax / T=E9l=E9copieur: (613) 954-0481; 943-1286=20

herd_at_NRCan.gc.ca / herd@RNCan.gc.ca
Received on Wed 26 Mar 2003 07:42:09 PM PST