[Rockhounds] CAN YOU REALLY FIND MICROMETEORITES IN YOUR GUTTER? WELL…

[Kreigh Tomaszewski]

The black magnetic flecks in sand are almost always magnetite.

On Sun, May 19, 2019 at 11:03 AM THE HAMMER <hammerron at hotmail.com> wrote:

> When I was a kid, I used to drag a magnet across sand and save the small
> black bits attracted by the magnet.  I used to call them iron filings,
> though I do not know if that is the proper term for what I had.  In
> hindsight, I wonder if any of the material could of been meteoritic?
>
> On 5/16/19 5:59 PM, Kreigh Tomaszewski wrote:
> > I collect meteorites <https://www.youtube.com/watch?v=TuDfZ2Md5x8>, and
> > have quite a few knocking around my home office. Some are big —
> fist-sized,
> > with one I bring with me when I give talks about impacts so people can
> hold
> > a piece of an asteroid in their hand — but most are pretty small, like
> the
> > size of a finger from the last joint to the tip. A few are pebbles
> > (generally well-known ones with special scientific interest, making
> bigger
> > pieces hard to obtain), and a couple of are sand-grain-sized (one is from
> > the Moon and the other from Mars).
> >
> > While I don't collect them, there is another kind that’s even smaller:
> > Micrometeorites, usually smaller than a millimeter across, some so teeny
> > you need a microscope to see them clearly. Bigger ones (say, a tenth of a
> > millimeter and up) are usually spherical or close to it, because they
> melt
> > completely as the ram through our atmosphere at hypersonic speeds, then
> > solidify after they've slowed down to subsonic speeds (in fact they
> > probably fall the rest of the way extremely slowly due to their size).
> >
> >
> https://www.syfy.com/syfywire/can-you-really-find-micrometeorites-in-your-gutter-well
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