[meteorite-list] The Term "Planetary"

From: Walter Branch <waltbranch_at_meteoritecentral.com>
Date: Fri, 18 Mar 2011 19:48:21 -0400
Message-ID: <026401cbe5c6$f7f11b90$0402a8c0_at_Desktop>

Hello Ryan,

The Earth's moon is very large, relative to the planet it orbits. In the
astronomical literature, the earth-moon system is sometimes refereed to as a
dual planetary system. The dividing line between planet-moon and
dual-planet seems to be whether the center of gravity (barycenter) of the
bodies is either in space or beneath the surface of one of the bodies (don't
quite me, though I may be wrong).

I have seen Pluto-Charon sometimes referred to as a dual-planetary system
(though now I guess it would be a dual dwarf planetary system.

-Walter

----- Original Message -----
From: <fallingfusion at wi.rr.com>
To: <meteorite-list at meteoritecentral.com>
Sent: Friday, March 18, 2011 2:44 PM
Subject: [meteorite-list] The Term "Planetary"


To the list,

I was sitting here reading some emails, and just thought...

Who in the world ever came up with the term "Planetary" in reference to
meteorites.

First of all, our Moon isn't a planet.. and secondly, to my knowledge, the
only "Planetary" meteorites in current existence have an origin of Mars.
Hence, "Martian" meteorites. Did I miss the big announcement of those from
Venus and Mercury?

Regards,

Ryan

Sent on the Sprint? Now Network from my BlackBerry?
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Received on Fri 18 Mar 2011 07:48:21 PM PDT