( intro music )
( muffled radio noises )
( swooshing sound )
( electronic hum )
( audience applause )
Well I'm really happy to be here
with everybody this evening and share with you
a bit of a potpourri from an alien planet.
From an alien planet that is near and dear
to our hearts because we live on it.
And because we live on it, we think we know about it.
But the truth is that there are huge,
vast tracks of the surface and particularly
the subsurface that are really unknown to us.
And so each one of these little planet-lets
that go to make up our planet actually harbors
life forms and conditions that are radically different
from what we experience on the surface.
And my way of substituting for getting into
my rocket ship and cruising the galaxy looking for
cool life forms, which is what I grew up wanting to do,
is to have stayed closer to home because
I don't have a rocket ship yet, come on NASA.
( audience laughter )
And try to explore templates for the kind of life that
we might find on the planets in our own solar system
and what kinds of signatures would those leave.
Well, National Geographic has played
a big role in my life.
And I had my first magazine subscription
as a little kid, courtesy of my cousin in 1968.
Early on in my attention to caves,
they sponsored some of our work, and this is
the centerfold from the January 2000 issue.
I actually was able to be a centerfold model.
( audience laughter )
And looking as glamorous as I usually look
in these kinds of deals, and there I am
with Diana Northup and Mike Spilde,
two colleagues from the University of New Mexico,
and I'm diving for phlegm ball mats totally suited up.
If you've read the magazine article
this time around you will know that we are
still working on that system 15 years later
and we are still mystified by the tremendous
amount of biological activity in what is to us
an extremely toxic environment.
This is why we're all duded up,
because we are kind of life form, humans,
and higher animals find this kind of environment
very toxic.
But we are still looking at snottites,
these are the famous snottites.
And I'm gazing lovingly at them.
( audience laughter )
And taking samples of them,
which we will haul back to the lab
and then try to poke them with sticks
and get them to grow and look
at their DNA guts and all that kind of stuff.
But this is not where my caving career started.
It actually also started by way of
a National Geographic special.
It was called "Mysteries Underground" in 1992.
And that same year, with several other colleagues,
I had published a paper suggesting that
the best place to look for life on Mars
was not on the surface of Mars,
but would be in the subsurface.
And I was looking for a way
to get into the subsurface of Earth
to see what we could find down there.
And I was way too poor to actually do drilling.
We couldn't get anybody to pay for it,
and we saw this National Geographic special,
and it said a couple of really important things
about the cave.
It said it was pristine, that it had been dug into,
which meant less contamination.
That it had a lot of sulfur,
and we already knew that Mars was a very
sulfur-rich planet.
And the third thing was that one of the geologists
from the USGS Geological Survey
said that he thought he had seen some kind of
little microbial life forms on some of the formations.
And so we were sold,
and we called him up and we said,
"You don't know us but we're from NASA
and we'd like to go into your cave."
So we trained for three hours ( laughs ),
which if we had known then what we know now,
of course this was completely nuts,
and then we went on an expedition
for five days into this cave.
Now this cave is a huge system.
It's 138 miles of mapped passage so far.
And exploration is still underway.
Of course we were captivated by
many of the scenes that you see.
This is a beautiful image of what's known
as the Chandelier Ballroom.
These are big selenite crystals.
But really the quarry that I am always after
is shown in these orange materials
behind where the young man is standing.
This brown stuff in the middle,
it's not as spectacular,
but this is where the real quarry lay.
And there are some of my little friends now.
These are all microorganism types
that are unknown to science.
In fact, virtually everything we find in the subsurface
is unknown in the databases
that we have of surface life forms.
The tiny ones there, we call them the tiny guys,
isn't that original?
( audience laughter )
These guys are about 100 nanometers across.
One of your hairs is about a 100 micrometers across,
so this is a thousand times smaller than that.
And these are some of the smallest life forms
that are clearly growing and alive
that have ever been found.
The ones with hairy bits sticking off them,
we call them smurfs ( laughs ) for obvious reasons.
And then the others are the death stars.
( audience laughter )
Well these are just a few of the microbial forms
that we see in the subsurface.
And this is really what got us going,
and really caused me to focus my career
from a lot of the surface extreme systems
that I had been looking at up until
that point in my career.
I just wanna dazzle you with cool stuff, okay?
So one of the amazing things about caves
is just how big the spaces can be underground.
Here's a couple of examples.
And if you've never been to Carlsbad
or Mammoth Cave or any of the beautiful
show caves around the world,
this is probably what you are looking at.
Something like that.
But there are many other peculiar
and amazing structures.
So, see all that white material
when you're actually there
it sort of sparkles like sugar.
There's 18 kilometers of this river underground.
This is Snowy River in Fort Stanton Cave,
about only an hour and a half away from my campus.
But the thing that gets us about this
is not just the spectacular mineralogy,
but all those dark streaks on the wall.
That's where the real action is.
And you can almost hear them calling.
They're saying, "Hey, hey, stupid, we're up here."
( audience laughter )
In their tiny little microbial voices.
( audience laughter )
And when we take samples of those,
we can find that sure enough they are
made by bacteria that make their living
off a chemical transformation of minerals
that contain the element manganese.
This is a pretty exotic way of making your living.
They don't eat sandwiches for lunch like we do,
they eat rock and minerals.
And this is ubiquitous in these kinds of systems.
This is one of my colleagues crawling through
some of that beautiful white material.
In this material, besides its beauty,
it also contains fossilized microorganisms.
So we can see that the cave is preserving
not only the live guys, that we can go in
and look for now, but also the potential
for preserving that material into the future to be tested.
This is a potpourri of some of our little friends.
The upper left hand is spots of goo
and little colonies, and all of that is alive.
There are probably two or three thousand strains
of microbes in there, not a single one of which
is very closely related to anything on the surface.
This is in a lava tube cave in Hawaii.
The upper right hand side is
what under some circumstances would just
turn into an ordinary stalagmite dripping water,
saturated with mineral, and yet in some circumstances
it turns into nests of so-called cave pearls.
Why?
We think it's biology.
We think it's the gooey biofilm that microbes produce
that actually causes that to occur.
In a mine in northern Minnesota,
called the Soudan mine,
there are bore holes very narrow
that go down to much deeper levels.
And when you sample those deeper levels,
you still find microorganisms.
They are even more exotic in making their living
in a totally non-oxygen environment.
This is a salty, briny iron mush that they're living in.
And you can see little bubbles of their activity
coming up from below.
In that same mine, on a March afternoon in 1962,
the miners were told that the mine closed,
and they threw down all their stuff and left in disgust.
50 years later, what we find are these structures
that you can see, this tower of dark material,
actually growing on one of those miner's jackets
that had been discarded on that day.
And this is entirely composed of iron
and manganese-utilizing microorganisms
and the minerals that they excrete.
If you go to southeast Alaska and are lucky enough
to be able to find one of the caves that exist there
in the Tongass National Forest,
and you take a sample of some of the material
there and you bring it back to the laboratory
and look at it with a scanning electron microscope,
you will see this beautiful forest of crystals.
All of those filamentous things that you see
weaving through them are microbes,
and the microbes are facilitating
the creation of these beautiful structures.
Here, these pool, out of which these fluffy
foof balls, or poof balls we call them.
This is the Poof Ball Sea.
And this is a system that is always
right around or below freezing.
So you can see that the temperature range
within which we can operate is really great.
This system is in Ukraine.
This is one of the largest gypsum caves,
in the rock type gypsum, in the world.
It's between 90 and 100 kilometers of passage,
so it's a very big system.
And it's covered by these screaming red towers
that look sort of like stalagmites.
And the color is indeed as brilliant,
as you can see from the knife that's in the picture.
And when we look at those with
an electron microscope, we see this is not just mineral,
that it is composed of these tulip-shaped
microorganisms all glued together with iron compounds.
We don't know who those are.
Even something like granite,
and this shows a granite cave in northern Spain
with colleagues from Spain and Portugal and Brazil.
Just looks like an ordinary granite surface.
But actually the granite itself is sort of
a yellow color, and that gray color that you're seeing
is really composed of these little guys.
So fluffy strings of bacteria
are making their living on the inside of this granite cave.
And they are producing beautiful little
silica-containing speleothems,
or decorations as they're called.
Tiny little stalactites and stalagmites.
And they are doing that because by their very
life processes they're helping to dissolve that granite.
So individually they're very tiny,
but in the aggregate they're incredibly powerful.
Even in ice, which is particularly important
when we come to think about icy bodies
in our own solar system and the potential
presence of life in those systems.
This is Aaron Curtis, one of our graduate students
at New Mexico Tech, who's doing his dissertation work
on the ice caves
around the volcano Mount Erebus in Antarctica.
And not only are these magnificent caves
with beautiful decorations in them just like
you would find in a limestone cave perhaps,
but there are also life forms in those ices.
Here's one that looks like a twisted candy cane.
So there is nowhere that is bug free.
( audience laughter )
No matter what you hear on TV about
how you should live a germ-free life,
you should not believe that.
( audience laughter )
I wanted to give you a glimpse of a mystery
that we are pursuing and have been pursuing
for about 15 years.
And you can see some of the macroscopic evidences
of it in this beautiful little cave decoration here.
This is a copper mineral called chrysocolla,
and it is a beautiful blue color.
And when we first saw these we were entranced
and thought, "Gee, they seem to be gooey",
and they were gooey.
And we took samples of them and lo and behold
they had many microorganisms in them.
Since this initial effort, we found them
in many different caves around the world.
And they often contain structures that look like this.
These look like empty mesh stockings, right?
But we don't know what they are.
We don't know what kind of life form they are.
They all have the same pattern,
although there are variations.
And now we've found them in probably about
50 or 60 different caves around the world
in all different kinds of chemistries,
all different kinds of temperatures.
All different circumstances.
Some are shallow, some are deep.
We don't know who these are.
They're not fungi, they're not amoebas,
they're not bacteria.
We don't know.
So 15 years of pursuing what I think of
as the wild
even with all of the science that we have
at our disposal, and we still have aliens
right here underneath our feet.
I want to end with this spectacular image
by a wonderful cave photographer, Carsten Peter.
This is the Naica system in Chihuahua in Mexico.
National Geographic has done a wonderful
article on that in 2008.
There have been two National Geographic
television specials that we've been
privileged to participate in.
And yes, those crystals are that big.
And the reason that we're in these little orange suits
is not to keep us warm as you might think,
but to actually keep us cool enough to work in there.
So are essentially in suits packed in ice
in order to keep us from dying from the heat in there.
The heat ranges from about 105 degrees
to perhaps well over 140 degrees Fahrenheit.
And this is just not survivable for humans.
And yet this entire system has microbes everywhere.
It has them in the walls, on that orange material.
And particularly interesting to us,
it has them in little tiny fluid pockets
within the giant crystals.
And because the crystal growth rate has been
measured and also age dated, we know
that the samples that we were able to take in some of those
crystals are at a time depth of between
about 10 and perhaps about 50,000 years.
So we have been able to go into the crystals
and use these little pockets of time capsules.
And not only were we able to find DNA
and organic remains of microorganisms,
but we were able to actually bring a lot of them
into culture alive.
So we're very excited about this because
this shows that microorganisms can tolerate
significant periods of time,
geologically significant periods of time,
in a state of relative inactivity,
and yet still remain viable,
still remain life-containing,
and still able to be brought back to life so to speak
once they get released from these materials.
So our own mini solar system underneath our feet
is acting as practice really as we try to do
what my colleagues have suggested.
And that is take our knowledge, take our science,
take our melding of the discipline of science
with the magic of exploration and the beauties
of what we see and what we experience
and combine those together in order to
advance our knowledge of the universe.
So we are right on the cusp of this
kind of exploration.
And the work that I and my colleagues do
will hopefully help to give us models
for how organisms can make their living
in this amazing array of planets
that we have in our solar system
and this amazing array of planets
that we apparently have in our galaxy and our universe.
Thank you.
( audience applause )
( outro music )