Ok. So are you ready to be transported out of this world?
Yeah. All right. Well, imagine that you were able to step into a time
machine and go back far, far back in time to a time and place where the
solar system was not even existing at the time place in the galaxy near a
massive star that's about to go supernova. Imagine this is about 5 billion
years ago.
So you see the supernova going off from a safe distance, of course, and it
releases the energy equivalent of something like quadrillions upon
quadrillions of nuclear bombs. And the shock wave that goes out, it
compresses some of the interstellar gas and dust that's nearby and it
triggers the formation of new stars. One of these new stars is our very
own star, the sun. And now imagine that you're looking at the swirling
cloud of gas and dust around our newborn son and you look closely and it's
cooling down slowly and you start to form the very first solids, the first
millimeter centimeter size solids from this cloud of gas and dust and
these little pebbles that are forming, they collect together, they stick
together they form these little rocks and then those stick together, they
form these boulders and the boulders stick together to form asteroids and
the asteroids accumulate together to form planets like the earth.
So
if you were to grab a little bit of the earliest pebbles that were forming
in that environment, squish them together, put them in a bag and bring
them in that time machine back to the present day. What might that look
like? This is exactly what it would look like. And this is a meteorite.
So, meteorites really are the remnants from that earliest phase of the
earliest history of our solar system. They are, in fact our time machine
to be able to go back in time and look at that space and time when our
solar system was just starting to form,
I'm gonna step back just a little bit and, and talk about what a meteorite
really is. These are rocky or metal rich objects that come from elsewhere
in our solar system. Most of them have traveled billions of miles in
interplanetary space before they've fallen on the earth and they've
survived passes to the earth's atmosphere and they fall on the surface and
can be recovered.
So that's meteorites. Now, what my goal is in this talk
is to essentially convince you that meteorites are not just some oddball
rare phenomenon. They are fundamental to our understanding of our past and
of our future. My work, which I'm, I'm really passionate about, um, it
basically involves figuring out uh clever ways of decoding the information
that's encoded in the chemical chemicals that make up these rocks. And
we're doing that in my laboratory by looking at the different components
that make up these materials and trying to learn something about when they
formed and how they formed.
So, what I'm gonna do today, there's so much wealth of information that
we've garnered from uh from meteorites that it would be impossible to
cover that in the, in the space of 15 minutes here. What I'm gonna do
though is to condense that down to five essentials, five things that
anybody who cares about the future of our planet, anybody who is curious
about our past uh should know about meteorites. So the number one thing is
that meteorites tell us that the age of our solar system is 4.5679
plus minus 0.0003
billion years old. How do we know that age? This is actually measured in
my laboratory using radioactive elements that we use as clocks in these
meteorites. This is almost like figuring out the age of a middle aged man
to um within a day. So you can exactly precisely determine exactly the day
, the month, the year that this person was born to within a day. So this
is an extremely precise age, but it matters, we need to know exactly what
the context is for all of the events that happened following the formation
of our solar system. And this is the age that gives us that context for
the timeline of everything else that's happened in our solar system.
Following the initial formation like the formation of the planets
formation of the earth and the moon, the origin of life in our planet.
Number two, there are materials preserved in meteorites, little tiny dust
grains that are older than our solar system. So this little vial that you
see here that's got this cloudy material in the bottom. These are billions
upon billions of tiny diamonds that condensed in the atmospheres of other
stars before the sun was even born by looking at the chemistry of these
little tiny grains. We can learn something about the evolution of the
galaxy before the sun was even born.
Very cool.
So you think that meteorites are rare? Well, think again, because you're
actually standing on a planet that's a huge agglomeration of a ton of
meteorites or more than a ton of meteorites really um meteorites. You can
think of them as the lego building blocks of planets like the earth and
the moon. This actually is a picture of actually multiple images that were
taken by uh a NASA spacecraft called the Deep Space Climate Observatory. I
love these images. Uh They're some of the best selfies of our, of our home
planet. Um And you can see the moon moving in front of the earth here and
it looks very serene, but this is nothing like what our planet looked like
4.5 billion ago years ago when it was just starting to form, after the
formation of our solar system, it was forming by the agglomeration of
giant meteorites coming together to form, form our planet. And this
process was so energetic that the entire surface of our planet at the time
was covered with an ocean of magma. And as the earth gradually was cooling
down, uh there was another huge impact of a mars sized meteorite that
crashed into the earth ejected this debris into orbit around the earth.
And we think that the moon actually formed from a coalescence of that
debris that was surrounding the earth. And so meteorites really are
essential to understanding the origin of the earth. And the moon
number four meteorites likely brought the raw materials for life to the
early earth. So this is not just organic compounds like the amino acids
that were brought in by some of the types of meteorites that we have in
our collections, but also uh bio essential elements like phosphorus. They
were brought in by meteorites and eventually led to the type of chemistry
that was required to take us from, from the chemistry to life. And so the
reason why you and I are here today, it could very well be because of the
material that was seeded to the early earth by meteorites.
And number five meteorites have changed the course of the evolution of
life on our own planet. And as you all, well, most of you probably know
that 65 million years ago, there was a large b light, something like 10
kilometers or six miles in diameter that crashed into the Yucatan Basin.
And it resulted in the extinction of more than three quarters of all
species on the earth, including the dinosaurs.
So that particular event, that extinction event was also important because
that's what led to the possibility of a small warm blooded mammals to
flourish and eventually made the way for humans to be able to exist here.
And that's the reason why you and I are are here in this place and this
time. So that's, that's amazing, right? So meteorites five ways in which
really they define our past and the course of evolution of life origin and
evolution of life on our planet. What about the future? Well,
our cosmic neighborhood is teeming with asteroids,
these red, yellow and green dots that are shown here in this visualization.
They're showing all of the known media known asteroids at the current
time and most of these are larger than about a kilometer. There are about
hundreds of thousands of other smaller asteroids out there that we've not
even detected yet. So these smaller asteroids are probably not going to
cause the type of glo global catastrophe that killed off the dinosaurs,
but they're probably enough to cause a lot of death and destruction if
they were to hit a large populated area. And just to sort of make that
point, um, many of you probably been up to me up in northern Arizona and
that was actually created by an object that's about, that's estimated to
be about 100 ft in diameter. And it created a crater that's about a mile
wide. So this is an event that happened about 50,000 years ago now. And at
the time when this happened, the energy that it deposited was the
equivalent of something like 100 and 50 atom bombs. And so that you can
imagine the type of destruction to plant life and animal life that
happened in this part of the continent as a result of that impact. And
that could be devastating for any large city if it were to happen today.
Now, that event happened 50,000 years ago. And the probability we estimate
for uh an impact that size 100 ft or so in diameter uh to happen is it's
estimated to be once every 50 to 100,000 years. So that's something we're
basically due for another one. It could happen next month or it could
happen 50,000 years from now. But it's not a question of if it's a matter
of when there's going to be a large asteroid that's gonna be on a
collision course to the earth. And so what are we gonna do? About it. So
all of the natural hazards that we know about asteroid collision is the
one that could essentially wipe out our species. But it's also the one
that is imminently preventable.
How are we gonna prevent it? Well, there's 22 ways that we actually,
there's two things that we have to do. It's not one or the other. We have
to be studying meteorites. We have to be studying asteroids to understand
their chemistry, their structure. Uh We have to be looking at the how the
orbits of these asteroids evolve. And all of these pieces of information
will be necessary to develop the strategies to redirect asteroids that
might be headed on a collision course of the earth. And then of course, we
have to also inspire the next generation of uh of Children of kids to be
willing to invest in the future and to be good stewards of our home planet.
So we are actually doing all of these things. Uh We're studying
meteorites, we're studying asteroids trying to understand what we can
about their composition about their structure. We're also using space
rocks to inspire kids of all ages and it's actually kind of a, a wonderful
thing. I don't know if you've ever experienced that when you see a 10 year
old, when they, when they were totally enthralled with something I've seen
these kids that when you give them the space rock to hold in their hand,
they are completely awe inspired. Just knowing that they're holding
something in their hand that is older than the earth, that's the oldest
rock in the solar system. It's an amazing thing to watch. And I wanna be
able to use that same inspiration to excite or spark an interest in stem
fields. Basically science, technology, engineering, math. So using space
rocks as a vehicle for, for inspiring that kind of interest, um How are we
gonna do that? Well, we've been doing that locally um for many, many years.
But what we'd like to do is to extend that globally. And we're doing,
hoping to do that by taking kids on a virtual field trip of the solar
system. And how we're gonna do that is we're gonna create an immersive
virtual environment. And this is something that the Center for media
studies is collaborating with the Center for um education through
exploration here at A SU and we are developing this immersive environment
where you'll be able to walk into the vault of our meteorite collection.
You'll be able to go to any one of the drawers and open them up and we
have 3d color laser scans of all of our meteorites that you can basically
pick up a meteorite from a drawer and look at it in three dimensions to
experience it as a three dimensional object. There'll be embedded videos
that will provide information about the samples and what we're learning
from these types of materials. And so we'd like to be able to make this
really exciting for kids to be able to explore places in the solar system
where they may some someday hope to go perhaps and maybe they will never
be able to go, but they will be able to vicariously go there through
looking at these rocks. They'll actually get to be geologists studying
rocks on other worlds.
They'll be able to go to places like this primitive asteroid like this
asteroid. It AAA and look by looking at rocks like this one which we think
come from asteroids like this, they'll be able to visit the asteroid Vesta.
This is the second largest asteroid in the asteroid belt. And we think
that this is actually a small planet which underwent complete melting
early in the history of the solar system such that uh the all of the iron
nickel metal sank to the core and you have a dense mantle and a lighter
crust just like the structure of the earth. And in fact, we have
meteorites in our collections that come from the crust of this asteroid.
There's a large impact basin in the southern part of this asteroid which
was uh studied quite well actually by a NASA spacecraft called Dawn. And
we now know that these types of meteorites that we have in our collections
come from this very asteroid. And so we'll be able to explore the geology
of this one asteroid by looking at these things and then of course, there
are meteorites that we know come from the moon. And so we'll be able to
explore, the kids, will be able to explore the geology of the moon by
looking at rocks like this one which we believe comes from the highland
part Harlem highlands of the moon. And then finally, there's not been a
sample return a spacecraft that's gone to Mars and brought back samples.
But we've got these free samples from Mars. These are meteorites that come
from Mars. And this is an example of one that comes from an area on Mars
that had volcanism happening on it um about 200 million years ago. So this
is a relatively young rock that's coming from the surface of Mars. You'll
be able to do geology by looking at these, these samples and trying to
understand the history of that planet through these rocks. And so the goal
really for us is to try to make it really exciting for kids uh to study
the space rock to basically um learn something about places where these
rocks come from, to explore the solar system through them to be inspired
by, by looking at these uh by trying to understand the environments where
they form. And we want to inspire them to be curious about not just the
planet that they live on but the solar system and the universe that they
inhabit. And to recognize that for the first time in the history of this
planet. There's a species that inhabits our planet as human beings that
have the capacity to actually do something about an asteroid that might be
on a collision course to the earth. So
I believe that we can use space rocks as a means of inspiring kids to
recognize that the future is what we can, what we choose to make it. Thank
you.