From: "ronkean at juno.com" <ronkean at juno.com>
Date: Tue, 1 Jul 2008 07:37:22 GMT
To: WSFAlist at KeithLynch.net
Subject: [WSFA] cosmic dust
Reply-To: WSFA members <WSFAlist at KeithLynch.net>

-- dicconf <dicconf at radix.net> wrote:

One experiment I've seen recommended for kids is to lay out a fresh
sheet of newsprint at night (dry and weighted down) and check what
has landed on it in the morning; a few will be meteorites. They
tell me that many thousands of very tiny meteorites reach the
earth every day.
*
With dry newsprint, I would worry that any wind would likely just blow a=
way most of the dust which happens to hit the paper.  Another possibly b=
etter way to do that experiment would be to lay some strips of transpare=
nt packing tape on paper, adhesive side up, holding the strips in place =
with some small pieces of tape here and there.  That way much of the dus=
t which hits will stick to the exposed adhesive, and the experiment can =
be later examined indoors with strong light and a magnifying glass, or b=
etter, a microscope.  It should not make any difference whether the coll=
ecting is done during the daytime or at night.

To minimize the amount of terrestrial dust and pollen, the collecting sh=
ould be done when and where the air is least dusty - a few hours or a da=
y after a spell of rainy weather (but not so soon after the rain that so=
me new micrometeorites have not yet arrived to replace the ones washed f=
rom the air by the rain), far from busy streets and roads, when the sky =
is mostly free of clouds (micrometeorites can be 'caught' by clouds as t=
hey can nucleate the tiny water droplets which make up clouds), under op=
en sky (not under trees), and when there is practically no wind to kick =
up terrestrial dust.

Ron Kean