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Language: en
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you're watching a Nova science Now video
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podcast luckily for us asteroids as huge
as the one that knocked out the
dinosaurs don't hit Earth every
day but a surprising number of smaller
rocks do meteorite Hunter Rob Matson
invited Nova science now host Neil
degrass Tyson to the Mojave Desert to
for himself so what is this place you
drag me to here what what do you do here
middle of yeah yeah this is coyote dry
lake it's uh place to seen Lake that
drained and meteorites have been
collecting here for 14,000 years
meteorites fall all over the Earth they
fall in the oceans they fall in your
backyard but you have a lot of
distracting things to make it difficult
come out here and uh meteor rights
should stand out like a sore thumb do
you have any on you right now you have
uhuh um is it metallic or rocky
these this is a Stony meteor right so I
see it has the fusion crust still on it
there crust on it yeah it forms a crust
from the heat of Entry through the
atmosphere mhm and you can see it's
already rusting meteorites don't like
being on Earth CU we have oxygen and
water and uh iron they they can go a
billion years in space and come to Earth
and they rust and corrode and don't have
very long lifetimes so you you brought a
refrigerator mag I brought a magnet and
you can see it sticks pretty well whoa
whoa so how many meteorites have how
long have you been looking and how many
have you found I found my first
meteorite here 5 years ago yesterday
okay been searching here for a while uh
it was not the first location that I
found a meteorite but here on this lake
bed I found uh 23 23 meteorites and you
know how much area you've covered right
and we know that how old the lake bed is
MHM and we presume that meteorites are
falling everywhere on Earth so you ought
to be able to calc
exactly right we know the area of the
lake we can count how many meteorites
we've found uh in our very detailed grid
searching we like to think we haven't
missed anything which of course isn't
true we've missed a few things but we
can set a lower limit by extrapolating
the area of this Lake to the whole earth
to the whole earth and what do you get
we get about 20 to 40,000 meteorites a
year hitting the Earth hitting the
Earth sounds like a lot but the Earth's
big so any one square mile might see a
meteorite you know every Thousand Years
mhm mhm so when you just spot a rock do
you know just at a glance the likelihood
that it'll be a meteorite or you are you
checking every single rock that you see
no most of the ones that you'll see out
here have a the wrong color they have
the wrong texture on the outside every
once so you don't even bend down to
touch those yeah you're bending down
enough picking up enough rocks during
the day you like to avoid that as much
as possible your back gets a little sore
okay so it helps know a little bit in
advance like this this is it's gray it's
not likely to be a meteorite I'm going
to bend down cuz I haven't done this
much yeah notice it's a little bit
purple it's another color that tells you
not a not going to be a meteorite throw
it back throw it
back and I got one here that's another
purple one it clearly is different in
character structure and density from the
other ones you've showed me right so I
just throw it back we call it a
leverite okay
leave her right there leave leave it
right there
okay the other term we have is called
meteor wrong that's metor wrong that's
reserved for a rock that is real
promising and you'll pick it up it ought
to be a meteorite and you look at it you
see it up
close the medor wrong the medeor
wrong tune in this fall to learn about a
potentially deadly asteroid heading our
way or join us online at pbs.com /n NOA
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