[meteorite-list] Meteoroids Before Meteorites

From: Chris Peterson <clp_at_meteoritecentral.com>
Date: Thu, 12 Mar 2009 18:50:29 -0600
Message-ID: <C83F54CB448145E39CAEAAE33DFD968A_at_bellatrix>

Hi Eric-

Obviously, meteoroids don't have fusion crusts, but that doesn't mean they
have light colored exteriors. In general, just about everything orbiting the
Sun has proven to be darker than expected. Being in a vacuum doesn't mean an
object is in an inert environment. Millions or even billion of years of
bombardment by interplanetary dust, solar wind, and radiation does have an
effect.

As you observed, our few closeup images of asteroids show dark surfaces, and
meteoroids are nothing but fragments of asteroids. There's no way of saying
for certain, but I'd put my money on the meteoroid parents of meteorites
like West having fairly dark surfaces most of the time.

(BTW, don't forget that the surface of the Moon is as dark as fresh asphalt;
rayed craters show that there is lighter material beneath that, at least in
some places.)

Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com


----- Original Message -----
From: "Eric Wichman" <eric at meteoritewatch.com>
To: <meteorite-list at meteoritecentral.com>
Sent: Thursday, March 12, 2009 6:31 PM
Subject: [meteorite-list] Meteoroids Before Meteorites


> Hi all,
>
> While looking at photos of our most recent extraterrestrial visitor, the
> West meteorite, I was wondering what the "meteoroid" looked like while
> floating around in space... Look how nice and white this piece is on the
> "inside". http://www.rocksfromspace.org/133g_Interior.JPG Fusion crust is
> only formed while entering our planets atmosphere. Meaning that this
> meteorite was obviously whitish in color while still a meteoroid. Right?
>
> Space is a vacuum, and a vacuum preserves things right? Look at the moon
> and all the wonderful craters and how wonderfully preserved they are. The
> moon never changes color except when viewed through our atmosphere. From
> space it looks the same as it did millions of years ago.
>
> Does this mean that the West meteoroid, while in space and "before" it hit
> our planet, was white? I mean, it's not like the minerals that make up the
> meteoroid change colors before hitting our planet. Right?
>
> I guess the reason I ask this is that we all see photos of asteroids that
> are dark gray, gray-black or brown blobs of space rock floating around the
> solar system. I think our perception of meteorites are quite different. We
> tend to think of rocks from space as dark rocks floating around aimlessly
> and randomly bumping into one another occasionally sending pieces our way
> to be pulled in by our planets gravity.
>
> Are there huge white rocks floating around out there? And if so, wouldn't
> they be slightly easier to spot than a dark blob of an asteroid?
>
> I hope these aren't dumb questions.
>
> Eric
Received on Thu 12 Mar 2009 08:50:29 PM PDT