>> From the Library of Congress in Washington, D.C.
[ Silence ]
>> I'm Peg Clifton, Research Specialist
in the Science Technology and Business Division.
Today we launch the 7th year of our collaboration with NASA Goddard.
It's my pleasure and privilege to introduce to you,
Dr. David Grinspoon who will make the formal introduction
of today's speaker, NASA Astrobiologist Pamela Conrad.
Dr. Grinspoon is the first holder of the Baruch Blumberg NASA/Library
of Congress Chair in Astrobiology.
The Chair was established in the fall of 2011
and is a distinguished senior position whose holder undertakes
sustained research at the intersection between the science
of astrobiology and its humanistic aspects particularly its
societal implications.
Prior to his selection, Dr. Grinspoon was the Curator
of Astrobiology in the Department of Space Sciences
at the Denver Museum of Nature and Science.
He is a well known researcher in planetary science,
the author of Lonely Planets: The Natural Philosophy of Alien Life
and tweets at hashtag Dr. Funky Spoon.
[Laughter] While in his position here,
he is examining choices facing humanity
as we enter the Anthropocene era,
the epic of when human activities are becoming a defining
characteristic of the physical nature and functioning of earth.
And he also happens to be on the science team
for Mars Science Laboratory as co-investigator
on the radiation assessment detector, RAD, on the Rover.
Please welcome Dr. Grinspoon.
[ Clapping ]
>> Thank you, good afternoon.
Thanks, Peg.
Well I'm very happy to introduce the first speaker in this year's series
of talks in the ongoing collaboration
between the Science Technology and Business Division of the Library
and NASA Goddard Space Flight Center.
This is the 7th year of these programs on subjects in earth
and space sciences and in addition to today's talk on Mars
and the Curiosity Rover, this year there will be programs
on hurricanes, managing satellites, exploring possible other earths,
and finally our place in the cosmos.
Today's speaker, Dr. Pamela Conrad, Pan Conrad, is an astrobiologist
and mineralogist with the Planetary Environments Laboratory
at the NASA Goddard Space Flight Center in Greenbelt.
She has worked for the past several years on the development
of approaches and measurement techniques for assessment
of habitability in planetary surface environments.
Her planetary science interests include the comparative early
evolution of Mars and Earth and the measurement
of habitability potential on rocky bodies of the solar system.
She is Deputy Principal Investigator and Investigation Scientist
for the Sample Analysis at Mars or SAM instrument suite
which is presently exploring [inaudible] crater on Mars as part
of the Mars science laboratory mission.
Her extensive field experience revolves
around characterizing the edges of the habital zones
in deserts both polar and temperate.
Since her involvement with the Mars Science Laboratory,
Pam has become interested in the measurement of the noble gases
and what they can tell us
about planetary differentiation and evolution.
Pam began her higher education journey with a B.A.
with a distinction in applied music from George Washington University
where she then obtained a Master's in Music Theory and Composition
and then a Master's in Geology followed by the PhD
in Geochemistry and Mineralogy.
Please join me in welcoming Dr. Pamela Conrad.
[ Clapping ]
>> This is kind of cool because I was at the meeting
where we announced the first Bloomberg chair here in astrobiology
when David got the award.
So it's kind of a cool recursive thing here.
This is my favorite topic.
So I'm really happy that I get to talk to you about it
and it's a little bit tongue and cheek
when I call it extraterrestrial real estate assessment.
However it really is that because when you go to look
at a prospective home, you think about your requirements.
Is there room for a garden?
Does it have a fenced in yard for your dog?
Is it near a good school?
Can you get onto the beltway easily?
Is it too noisy and so forth.
We do exactly that process when we try
to define what the requirements might be for life both
on this planet and on another one.
Sadly we have no clue what life would look like on another planet
which is problematic because what's good
for one is not necessarily good for another.
So what we try to do when we do something so poorly defined is try
to come up with those features of life on our planet
that we think might be applicable to life elsewhere.
So while we actually do our own exploration today,
I'm going to do a few things.
One, I'm going to talk a little bit about the requirements for life
that I, personally, think might be relevant to life somewhere else.
Two, I want to talk a little bit
about how we approach extraterrestrial real estate
assessment by analogy in the field on earth.
And three, I want to give you an update on what we're doing
with curiosity at Gale Crater.
And if we can tie all of that together in a reasonable time span,
I'm going to leave plenty of time for questions.
I'm going to try not to talk too fast and so if you see me flipping
through slides quickly, it's because I want to get to the juicy bit
so that you can talk as well.
So you all probably know that we're on Mars
or if you don't know surprise, we're on Mars.
And it was a very difficult journey.
I've been working on this project since 2004
when we wrote all the proposals
for what we called the Payload investigations.
A Payload investigation is not just an instrument that made it
onto to the Rover and got selected for the team.
Sometimes it's a suite of instruments
but it's also the set of experiments.
Things that we proposed to the scientific community to do on Mars
and then by competition, the instrument teams
and the investigations are selected.
So writing such a proposal was very daunting.
I participated in 5 proposals even as the lead of the one.
One got accepted and that's the one that I work with today and I will,
of course, be talking a little bit about it.
And the primary goal of the mission, the reason why we're on Mars is
to try to figure out does anything live there or has it ever done so?
And to do so, we have to compare it to earth because we have a sample
of one planet where we know there's life and it's this one.
And it's very difficult to, in an objective way,
explore a system that you are within.
So because we have no choice but to do that,
to understand our own planet, if we can look outside of that,
we actually in a way where we keep changing our perspective,
going inward and going outward and going inward,
we learn something about our own planet.
And we learn some things about Mars by the things that we have learned
about our own planet and we just continue this process recursively.
Now you can see just from the picture, I have to dumb things
down for myself quite a bit because I came to science late in my career
and I'm not so good at quantitative things.
So I do them pictorially and the obvious thing here
but I should mention it for a specific reason is
that Earth is a lot bigger than Mars.
So when the planets form, they accrete from the inside out.
Little particles glob together and form bigger particles
and form bigger particles and bigger particles.
And the gravitational attraction of these globs
of stuff holds the planet together but when they stuff stays together,
it gets heated up and as the materials get heated up,
the outside cools at a different rate than the inside.
So what that means is the raw materials change.
[Coughing] What they do is we call it differentiation.
From the inside out you get layers.
So a planet is a layer cake and what you want to know is,
is the stuff that's on the inside available to the stuff that's
on the outside so you can do chemistry?
And the reason that it's important is because if it does nothing else,
the thing that life does is make new stuff out of old stuff
and when you run out of the new stuff to make products,
you have to go in the other direction.
In other words, you stop making new stuff.
Now we all can think of some obvious things that we
as organisms make aside from, you know,
bodily functions and that sort of thing.
We make technology.
We exhale particular gases into the atmosphere.
We make new food for ourselves.
We make a lot of stuff.
So when we look at Mars, we have to ask ourselves what can we make
on Mars with the stuff that's on the surface?
Does that stuff on the surface exchange places with some
of the stuff on the interior and in that way, we come to a new question
which is how dynamic is that planet?
What's going on to exchange materials
between the inside and the outside?
So we turn to Earth first and we say, okay,
how do we characterize our own planet?
Well, it's big.
It's warm.
It's wet. It's got a thick atmosphere
and one reason why we have
that thick atmosphere is we have this robust magnetic field
that keeps cosmic rays from coming down and frying us.
Now the thing about that magnetic field is this, it is generated
because the insides of the Earth are roiling and twirling and swirling
and they are generating in the magnetic field by their motion
because of the physical properties of those materials.
One thing we notice about Mars is, it's smaller.
Look at the color.
It's red. That means something.
Alas, it has no magnetic field.
Sadly, because it has no magnetic field it has lost a lot
of its atmosphere by mechanisms that we don't all agree upon yet.
We call it hydrodynamic escape in the major theory.
Because we don't have too much atmosphere, we're kind of cold.
The kind of water that can exist without the having the pressure
of the atmosphere to keep liquid phases in equilibrium
with solid phases and gases at a particular set of temperatures,
[inaudible], not so good.
So we don't have a lot of surface water on Mars.
And it's all because we don't have that magnetic field.
So it seems like a physics problem
that only the geophysicist might be deal with would not be so relevant
to the astrobiology that I'm doing but in fact,
it's all connected stuff.
So point number one for today's summary, everything is connected
to everything else but you probably already knew that.
So we sent Curiosity Rover to Mars to help us address some
of the questions that would give us clues
about whether it's alive or not.
You already know what our primary goal is
but when you do a science project, you actually become a little bit
of a systems engineer if you're going
to do it remotely on another planet.
And so you break it down into discreetly addressable
scientific objectives.
And so the objectives that we have for this mission are
to assess what we call the biological potential.
Could you conduct the business of metabolism?
Could you reproduce?
Could you do all those things that we see as being consistent with life
at least as we know it on another planet?
To do that, you've got to kind of know what you're working with.
So we want to understand the geology and geochemistry.
Those things that rocks tell us are the book
that gives us the window into the past on Mars.
The only thing that we can look at on the surface in terms of things
like water and air and that sort
of thing are efirmoral [phonetic] things.
What's happening right now?
We can tell you the dynamic at the surface but if you want
to infer what it was in the past, we have to look into the rock record.
We're also trying to understand what the role of water has been
and continues to be or not in modifying the surface of Mars
because when we figure out what's happening,
we can get an idea about, again, the dynamics.
The dynamics is what we keep going back to, time and time again
because life exists on a different time scale than the creation,
the maintenance, and the eventual decline of a planet.
So when you look in time is very difficult.
If we're at a planet that's past its prime or it hasn't gotten there yet,
we're out of luck unless we know how to look for the signs of what is
to come or what has been.
So try to keep that in mind as we go back and forth about the rocks
and the present environmental measurements.
We're also trying to understand the surface radiation and that's part
of the experiment that David is attached to,
the Radiation Assessment Detector.
That experiment is important because if we're going to go to Mars
or even send more stuff to Mars we need
to understand how difficult it is to withstand the slings and arrows
of galactic cosmic rays and solar energy particles not to mention UV
because it gives everything at the surface
of Mars a much greater degree of sunburn than we would get on Earth.
So Curiosity Rover is going to try to accomplish all
of these objectives with 432 scientists all getting along
and achieving consensus everyday as we plan what we are going
to do on a day by day basis.
One reason why I am able to come talk to you today is
because the sun is presently in between Earth and Mars
and we can't talk to the Rover.
So I'm off of tactical operations for another about 10 days.
So let's go back a little bit to the basics
about what makes a habitable environment and then I'm going
to ramp up the pace here.
We know that there are certain chemical requirements.
You need raw materials.
We talk about the magic set of chemical elements, carbon, hydrogen,
oxygen, nitrogen, phosphorous, and sulfur.
Now these elements are not the only elements that living things need
but these are found in everything that we know of that's alive
to a greater or lesser extent but there are trace metals
and other kinds of things that are equally important.
I don't have a font small enough to list everything that we need
and still put this slide together but you get the gist here.
We need more than just the raw materials.
We need energy so that we can do stuff with those materials.
Remember that take old stuff and make new stuff.
Or make new stuff and then make more new stuff but anyway.
We need water.
Now we don't just need water because it's a great solvent.
Everybody talks about that part but we need water
for a couple of other good reasons.
The types of chemical bonds that you can get with water are different.
They're special and we use those a lot in biology.
We also need just positively charged hydrogen in biology.
And what I like to think of as the primary importance of water
because we tend to ignore it the most, so I am a defender
of the underdog, is it is a fabulous thermal sink.
Water is what we call infrared active.
It's absorbs infrared.
That, by the way, is one reason why water is blue
because it's sucking up the red colors.
Water absorbs heat and it moderates the pace
at which we exchange heat with the environment.
We call that thermal inertia.
So that's an extremely important reason why water is important.
So when you put things together and do you get a habitat?
We don't know.
There are some intangible things
that make living things choose one spot over another spot.
So the idea is to try to figure out what those things are.
Sometimes it's a set of conditions.
So I like to just refer to that as the physics of the environment
and some of that has to do
with where you're fortunate enough to have been born.
It's not such a good idea to be that close to Jupiter.
It creates some problems like asteroids flinging themselves at you
and making giant pock marks right
in your favorite places near the Equator
but also the thermal environment has a function that has to do
with how close you are to the sun,
how often you switch what we call obliquity.
As you go like this, as you're spinning on your axis,
when your pole is facing more towards the equatorial plane
or the plane that defines your path around the sun,
you get a different set of climate conditions than you get
when you're more upright like this.
The dynamics -- well obviously the stuff we just talked about.
Smashing into a planet is bad news
if you're underneath the thing that's smashing in.
On the other hand, it could also be good news
because if it's bringing new stuff you need special delivery
to an extent, those impactors are good.
And there is a school of thought that suggests
that water was initially delivered to Mars and possibly
to Earth by cometary sources.
So, you know, you got to take the good with the bad and maybe some
of these impacts are good
but if you're underneath one it's hard to argue.
You mix that stuff up over time and you get a set of events that happen,
that have to be untangled in what we call time resolve measurements.
You can take a picture of something today
but if it looks different tomorrow that defines a sampling rate
over which you must make the measurements.
So we have to keep in mind while Curiosity's rolling that some things
that we measure at one time of day maybe be different
if we measure them at a another time of day.
So we have this awesome power supply.
It is called a multi mission radioisotope
thermoelectric generator.
Just think of it as a nuclear power source.
So we take a nuclear source.
We don't react it.
We just let it decay and give off heat.
We use that heat in a transduced manner to charge two big,
juicy batteries and then every day we run off the batteries.
We draw down the charge to, oh you know some extent
that we define the day before, and then we let it charge back
up to a certain extent before we resume operations.
So this big, juicy power supply enables us
to make measurements during the winter and at night
and that's something we couldn't do with Spirit and Opportunity
because we needed solar cells to run.
So big, juicy power supply.
Now the 10 investigations enable us to do things from a remote distance.
We call that remote sensing like take pictures panoramas.
We have a special laser zapper thingy
that can send a infrared laser beam at a rock about 7 meters away
for the maximum, maybe 2 meters close at a minimum,
and we vaporize the material making a cloud of plasma
which an optical missions detector then can identify its
chemical constituents.
It's called ChemCam.
We have things on our arm that we call contact instruments
because we actually reach the wrist of the Rover arm
down and touch the rocks.
We have two special instruments that live in the belly of the Rover.
I'm going to talk more about those in a minute
but they are an x-ray diffractometer and a suite
of mass spectrometers called SAM
which is the instrument suite that I work with.
And these instruments are distributed all around the Rover.
Some of the electronics is in the belly of the Rover
so we can keep it warm and some of the stuff is mass mounted as I told.
And some is arm mounted.
I'm not going to have time to go through this bit by bit
but I just wanted to show you a picture of where this stuff is.
And you see that thing on the front of the Rover
with this little circles, those 5 black circles.
That is a near and dear to my heart piece of hardware because I made it.
It is 5 cans that are hermetically sealed containing a silica brick
doped with two organic compounds
that are not found in nature anywhere.
Why do I love this thing?
Because this is the only thing we can drill with our sampling hardware
on Mars that we already know precisely what it is.
We have internal calibrants in our instrument and some
of the other instruments have calibrants but this thing you drill
into it right in the front of Rover just
like you would drill into a rock.
You process it through the whole sample processing system
and if you see weird stuff in this sample,
you know that it is not in the sample.
That's either weird stuff that is indigenously from Mars
or extra terrestrially -- I mean extra Marsally.
[Chuckles] Anyway, meteorites that hit Mars
or its terrestrial contamination.
So this is a very important calibrant for us.
It's only way of seeing whether our sample chain is clean.
I told you I'd tell you a little bit more
about the two analytical instruments.
So the x-ray instruments pattern which is the thing
on the left is the first x-ray diffraction pattern ever taken
on another planet.
I'm especially fond of this a, because I'm a mineralogist and b,
because my good friend, Dave Blake, is the Principal Investigator
of this and worked on this thing for more than 15 years
in his basement giving it off to friends when he lost funding.
Doing this and that to make it to Mars.
And I want to tell you it is so hard to persevere during times
of shrinking and expanding funding cycles, getting your lab given away
to somebody else, knowing that you've got other pressing needs
and this guy kept doing it and now he's on Mars.
That's a don't give up message.
And the sample analysis at Mars instrument, I can tell you lots
of stories about how hard it was for us to build our own instrument
but there we are, we're on Mars.
So what I'd like to talk to you about with regard
to this is how we do our daily business on Mars.
I'm going to skip this little bit of special stuff
about our specific instrument and I'm going
to go first to this picture here.
This is an actual photo.
This isn't a drawing.
When we landed on Mars, the heat shield separated
and we had this descent imager on the bottom of the Rover.
The bottom of the Rover is just exposed
to the atmosphere once we jettison the heat shield
and we took a picture of it.
And the thing that's really cool that I want you to see.
If you look at about 7 o'clock is where it's centered.
You see that kind of gray slash, you're going to see that again.
That's a dune field that's right near our landing ellipse.
And you can see it with such exquisite detail behind our
heat shield.
It's really awesome but that's not the only amazing picture we got
of our landing.
This was taking by the high rise camera
on another mission called the Mars Reconnaissance Orbiter.
And it is a picture of us dangling by our parachute
as we were aero breaking coming in.
The next thing that we saw that was a picture is own damn shadow
as we're sitting there on the surface of Mars.
This came in very quickly less than an hour after we landed
with the mountain in the background that we ultimately explore.
So the reason I'm showing you all these pictures is
to say sometimes making a measurement is not a measurement
that you can get quantitative about.
You can only get a qualitative feel for where you are by looking
at a picture but if you'll notice how cool it felt to look
at those pictures, that qualitative feel has a lot of intrinsic worth.
When we do our daily business,
we divide it up into different Sol types
so that we can model how much power it takes to do each of these things.
And it takes a bazillion watt of energy to do some of this stuff.
I don't want you to read all this stuff but I just want
to give you a flavor for our approach.
How we figure out what the heck it is we're going to do each day?
A lot of it is determined by how much resource is available to us
in terms of time, data volume, sending stuff back and forth
to Earth or just the sheer energy, the watt hours and each day
when we get together, we start with a report on the Rover health
and then different people have different functions.
And we lead a big science discussion group
that chooses what activity we should do.
We only have a couple hours to agree on what we're going to do
and then the rest of the hours
in our tactical cycle are spent actually writing the programs
and getting the instructions ready and reviewing, reviewing, reviewing,
and reviewing them again before we radiate the commands
up to the Rover.
And then the Rover does that stuff the next day.
And we do this every single day except during this conjunction time
we can't talk to Mars.
And so if we want to get a weekend off, that means we've got
to do 3 days worth of planning on Friday.
So we haven't done a full weekend off yet.
We had Saturdays off before conjunction
where we compressed the amount of time we spent on each day
and went right to planning what we call n plus 1, the next day or Sol
as we call it in the Mars language.
The reason we distinguish between a day and a Sol is
because Mars rotates at a slightly different rate than we do.
So a Mars Sol distinguishes it from the Earth day and because the rate
of time is slightly off, ultimately you get a time
where an Earth day doesn't match
up with a Mars day anywhere in the cycle of hours.
And so then you just do a correction.
It's kind of like leap time.
So here's a list of things that we have debated with regard
to what makes a habitable environment on Mars.
I'm not going to go through these and read them to you piece by piece
because ultimately you'll get to see these on the website.
But I want to put this here to show you that we have
to ask a discrete set of questions in order
to address the habitability issue.
And you start with requirements,
just like you do an engineering problem.
What does life require?
You got to try to put your head there so you can figure
out if the environment you're exploring meets those requirements.
You know, remember about the good elementary school
and the quiet and that stuff.
So in the case of a planet, we're looking at things
like the right chemical materials, the source of energy,
the right physics of the environment, what can we measure
about it that would give us a clue about whether
or not it meets some kind of requirement for some presumed life?
So I have developed, personally, a list of candidate measurements
which I've been exploring in extreme environments
on Earth for several years now.
And you don't have to read each one of these
but the point is I've divided them up into chemical measurements,
physical measurements about the environment,
geological measurements, and then some boundary condition
geographic things.
You don't make the geographic measurements each time you go.
This is to say you take into consideration
where you are on the planet.
We, with Curiosity, are near the Equator.
That's going to give us a different set of things to look for and to ask
about than we would be exploring if we were at the pole.
So that is that boundary condition.
There's another set of conditions which I did not put on this list
and we're not going to deal with it today but it has to do
with where you are astrophysically,
where is your nearest neighbor planet, how close are you
to your star, where are you in the evolution
of your solar system and so forth.
If we were going to apply these principles to exploring habitability
to other star systems, you would need to use that level of scale.
Okay. So I told you we're in a crater.
I told you we're near the Equator.
The name of the crater is Gale Crater and the thing
that is our ultimate destination is Mount Sharp which is this --
well actually it's officially called Aeolis Mons.
It's in the middle of the crater and it represents stacks, stacks,
stacks, and more stacks of sediment.
And if look at the drawing on the right side which has got kind
of a cut away cross section you'll see the drawings
of the presumed stacks of sediment.
That's why we want to go there because as we look
at those layers, it gives us time.
Each layers is a change in depositional environment
over some time and we think we'll get to see a lot of Mars history
by getting to those layers.
In the meanwhile, one of the things we're exploring is an area
which is a basin where 3 different kinds of rocks come together
and the basin is at the distal end of something called an alluvial fan
which is a bunch of stuff eroding
down that we can explore before we get to the more distal areas.
This stuff gives us an idea that the rocks we're deposited
and worked underwater.
The rocks that we're deposited and worked underwater were observed
on our way to our present location which I'm going to show you
in just a second but I want you to show the approach.
You take these pictures.
You try to identify materials that visually look different
and that lets you know it's a different kind of rock.
Then you start thinking about the properties
of the different kind of rock.
You can actually measure stuff like ah, thermal inertia.
That thing that came up earlier.
How fast do they change temperature?
Can one kind of rock heat up another kind of rock and kind
of moderate the temperature?
That's important on Earth.
If you're an organism living in Antarctica, in the sandstones
of the Beacon formation in the McMurdo Dry Valleys,
you get a lot of your heat from this underlying basalt which gets really,
really quite warm even in the middle of Antarctic day.
You can sit on it and it'll warm your buns.
[Laughter] Where we are right now at this junction
of these 3 different kinds of rock and this basin
that I told you about, we loosely call Glenelg.
We have formal names and we have informal names.
And we've got to come up with informal names
because as you use the principles of the U.S. Geological Survey
for mapping planetary features, they got to go
through this process before they're vetted but we have
to know what the thing is that we're referring to on a daily basis
so we can say is that that rock over there or drill this one over here.
So, you'll see a lot of formal names and informal names
and they actually have a rhyme to their reason.
We usually come up with a theme.
We make a list of available names
and each day we select a name for a new target.
When we look at the geological context as --
from my chart of different kinds of things you measure,
you see something interesting and that is
that the landscape defines different features
which in turn define different chemistry
which can make a difference to life on Earth.
This place which is in an area called Amboy [phonetic].
It's out in California in the Mojave Desert.
This is a drainage plain.
It's a flood plain and I drew that square.
That's not naturally occurring.
There's this one little tree there.
Just one tree.
Now I drew the square to include the tree.
If you look off to the banks of the flood plain, you'll see lots
of scrubbed terrain but the question that you have
to ask yourself is how do I decide how big an area I'm looking at?
What is the meaning of that one tree there?
Those are the questions we ask about that one rock there or this
or that feature that we observe on Mars.
We ask ourselves the same thing about different types of terrain
and other extreme environments.
This is Bad Water Basin on the top picture in Death Valley.
Those are the Joshua trees just driving along the highway
to get to Death Valley.
They only like to live in a certain type of chemical condition.
And that chemical condition is defined by elevation.
So they need certain temperatures and they need certain chemicals
and if you get that, you get the Joshua trees.
Same thing is true for the microbes in Death Valley living in this,
what we call, evaporite rock.
Water periodically inundates bad water
and then it mixes the chemicals around.
You see that skinny, green line in that hand specimen.
I don't know if you can get it from where you're sitting
but those are photosynthetic organisms.
And they only live in that spot, that deep under the surface
of the crust and no deeper.
And if you miss that one horizon,
you've missed a living thing that's in that hand sample.
So you got to keep stuff like that in mind when you're on Mars.
So we have done 3 kinds of things.
We've looked at stuff remotely and touched stuff.
We've actually scooped up soil and ingested it into the 2 instruments,
SAM and CheMin, that live in the belly of the Rover.
And we have now drilled a rock.
And we've learned different things about the physical properties
and the chemistry from each of these campaigns.
Now we get the picture show.
So the sand that we scooped is what we call a wind drift.
It's fine, grain material.
We think it's the kind of stuff that's blown
around globally on Mars.
And we measured it.
We scuffed the stuff with the wheel because we wanted to know whether
or not the Rover was going to sink in like quick sand
from an old time Western.
And as you can see, we didn't sink in but we got a nice scuff mark
of our wheel tread pattern.
When we scooped, what we saw is that there's some very fine grain stuff
and that there's these little concretion things.
And you see those little round things in there,
that's what we call the armored part of the soil.
We couldn't look at that just yet because the siv that scoops
and apportions the material into our inlet tubes makes all the materials
that are bigger than 150 microns unavailable to us.
So we haven't looked at that yet.
We're just getting ready to look at that stuff sometime in the future.
The picture that you see on the right shows you an important thing.
The physical properties of the rock and the soil,
in this case, make a big difference.
You see something about the processes that deposited the rock
that is the left panel of the picture on the right.
You see those striations.
They're called cross beds and that means
that that rock was either windblown sediment
or it was subaquesously deposited sediment and the shape
of those ripples in that rock will tell you which one it was.
Look at that photomicrograph taken
with an electron microscope on the right.
You see those holes?
Those holes are very important.
You don't get living stuff living in the space
between minerals in a basalt.
The stuff might live in a crack but the microbes can't live
because there's not enough room and basically when they make poo,
there's no space for the poo to diffuse away.
Not enough porosity and they would drown in their own poo.
[Chuckles] So porous base is important.
At that level, you have
to understand how the physical properties affect your ability
to do metabolism and that's what we're doing on Mars.
Physical features.
Physical features are everything from the temperature
of the environment to the radiation of the environment
to how often those things vary within the environment.
Is there wind?
What direction does the wind come from?
How strong is it?
Does it swirl around?
We care about wind because if wind is coming from here and going
to there, what we want to know is ah,
the source of the material that's being driven in by the wind.
So that's one reason.
Another reason could be, ah, there's wind.
Oh maybe we shouldn't deliver a sample
into our funnel when there's wind.
Oh, it looks like the wind is worse at 2 o'clock in the afternoon.
Let's deliver the sample at 6 o'clock at night.
Do you all remember when the Phoenix Lander was near the polar regions
of Mars and they had trouble delivering scooped sample
into the ovens of their Tega or their thermal evolved gas analyzer?
We learned from that.
We made little wind guards for Curiosity.
We studied the wind patterns.
We only delivery at favorable times.
So that is one reason why physics is important but another reason is
if there's a lot of wind, we want to understand the turbulence of air
and how well the gases mix.
So that when we measure the chemistry of the air,
we'll get an idea of whether it's representative of the whole planet,
whether it's representative of this one little area here
where smelly methane could be coming up or whether it's not
at all representative of anything because there's
so much turbulence you can't tell.
So that's a very quick and dirty overview of why you have
to understand the physics of the environment.
Let's take a look at this relationship here between radiation
and the density of the atmosphere or atmospheric pressure.
This is one of the coolest things we've measured since we got to Mars.
You see how those are opposite?
That tells you that even that thin
and weenie atmosphere is giving you some protection from radiation.
And you see this perfect correlation
between when the atmosphere is thicker, the radiation is less.
So if you would doubt before the utility
of this atmosphere even though it's kind of thing, it is at least good
for moderating some of the chemistry
and the dynamics of the Martian surface.
We have another kind of instrument that is, on a principle of physics,
able to measure how much hydrogen is beneath the surface.
Now we use hydrogen as a proxy for water.
We could see hydrogen or we could see hydrogen connected to oxygen.
We call that hydroxyl or we could see H2O or water.
Of course the other possibility exist
that we could see hydrogen attached to carbon
which would mean we'd have big beds
of organic stuff underneath the Martian surface.
Now while I don't think that is the case we can't rule it out
and it's important to keep an open mind and not rule out any stuff
that we can't definitively say is impossible.
So this is called DAN or dynamic albedo of neutrons for the way
in which we measure the hydrogen.
This instrument shoots the stream of neutrons
which are fairly weighty little atomic particles,
subatomic particles and they come back to a detector.
And how fast or slow they reflect off of the material
under the ground tells you how much hydrogen is there.
It's pretty cool.
And so this shows you how well the instrument is performing based
on a calibration test that we had while we were still
on the ground before we launched.
I'm not going to show you any DAN data to a great extent here
because the way the plot comes
out in tiny little histograms it's difficult to show.
Now I'm going to blast right through physics and get to chemistry.
I saved that for last because we have
so many ways of measuring chemistry.
Again, I want to point out that the first blush at looking
at chemistry is obtained by looking
at the physical character from an image.
One of the other very exciting discoveries we made was the effects
of running water when we found conglomerate which is a rock
that gets only made by the weathered and rounded pebbles of things
that have been aqueously altered.
That was a clue that water was there.
When we actually began measuring the chemistry,
we saw that there was indeed a lot of water there.
We also saw that there were other important chemical elements
that would tell us that maybe it's not such a bad environment
if you were trying to support life.
You'll see this spectrum taken by the ChemCam instrument,
a picture of rock from which we were able to deduce
that water had effected that rock and that there was also calcium
and that there was some carbon and that there was some iron
and other things that might be relevant for life.
Life has its own array of chemical elements just
like rocks have their own array of chemical elements.
And this is one of the cool things you can do
with geochemical measurements.
You see the thing with the green and the red and the yellow line
on the left that is the pattern
of chemistry associated with a particular rock.
It's measured by a contact instrument called the alpha particle
x-ray spectrometer and it's just measuring chemical elements.
You'll see across the x-axis on the bottom,
elements with an oxygen next to them.
We tend to calculate in geochemistry things --
what we call oxide weight percents.
Look at this picture on the right side.
So that's average terrestrial crust, average lunar crust,
and a couple of other, oceanic crust but I got to show you this.
This is cool.
So this big one here, can ya'll see that?
That's the geochemical distribution of a photosynthetic bacterium.
It's just what's on the surface and what you could measure
by this method but that is it to tell you that just
by measuring chemical elements you can get a pattern that is distinct
from the pattern of the rock stuff that is suspicious
and you can say ah ha, that does not match the other rocks.
It could just be a different rock but it could be something else.
You can measure the atmosphere which is what our instrument SAM does
and we have measured the atmosphere since we got to Mars
and we now understand the major mixing ratios
of important components so that we can understand what types
of more reactive gases mean if they emerge
from changes due to the seasons.
There's a set of reservoirs and fluxes that we can begin
to hypothesize about and that allows us to speculate on what it would be
like to observe an organic gas like methane as we have done
through observational astronomy.
We have an instrument that is part of our suite
which is tuned specifically to look for this methane.
Let's see.
Okay. We're still alive here, 38 minutes and counting.
So what we've done from looking at what we can see by the chemistry,
the physics, and the environment, let's just put together a picture.
It's not 3 dimensions in terms of 3D space.
It's 3 dimensions of thought space that allow us
to approach the complex problem of habitability in a matrix sort of way
where we can say check off this box.
Check off this one.
Check off that one and oh, you check off enough boxes and you begin
to suspect this could be a habitable environment.
So cutting to the chase in that regard, we have made a lot
of observations about present Mars and by looking into the chemistry
of the rocks about past Mars and what we have concluded is
that we seen nothing at this moment that precludes habitability on Mars.
That doesn't mean we have found organisms
or that we are saying Mars is inhabited.
It means we are saying that we don't see a show stopper.
So because we're only 8 months into at least 2 year baseline mission,
we'll be making many more measurements
and who knows what we'll find.
Let me show you where we are right now.
The Rover landed where that blue writing is
that says Bradbury Landing which we named after Ray Bradbury
who had died just shortly before our landing.
The end of that little gray line is where we are right now in a part
that we call Yellowknife Bay.
We have already drilled our first sample from the rock.
This is what the Bay looks like.
We picked it because the rocks have a texture that looks
like they were deposited underwater and they're filled with veins.
And those veins might tell us about some dynamic processes
through which the rocks have been altered from underneath.
We don't know.
We're going to try and find that out.
And as we pick targets, we drilled them and we investigated them
with the Chin Men [phonetic] x-ray detector --
x-ray diffractometer and the SAM suite of mass spectrometers.
And what we learned was that there was definitely alteration underwater
because we made a kind of mineral that we consider to be a holy grail
of alteration understanding water
because that is a good preservation environment for organic molecules.
You see how this is kind of hazy right there?
That's a philosicay [phonetic] or the scientific name for a clay.
The only thing that we measured
out of this rock was a huge amount of water.
You see where that says m18.
That means mass 18.
In our mass spectrometer that's water and so we're showing you
that there's a ton of water attached to the minerals in that rock.
So you already know that we're going to be going to Mount Sharp
after we do more analyses.
We're probably going to drill another hole and check
out some more features of Yellowknife Bay before we get going
on our long alpine expedition once our conjunction is over but I want
to just show you one more thing before we do the questions.
And this is an open mind exercise.
So when I was in graduate school, I had a topic called petrology
which is how you learn about the history of how rocks form
and the processes and how they manage heat loss and so forth.
And so the book we had was by this guy named McBerney.
And I had a colleague come to visit me sometime later when I was working
at the Jet Propulsion Lab at the time and he said, oh,
I see you studied using the McBerney book.
Did you ever see the self portraits?
And I said no, what are you talking about?
So he said every time he drew an image illustrating rock textures
in a microscopic thin section, he drew a little picture of himself.
So every page [laughter]
where there's a microscopic thin section there's a picture
of this little guy.
And so of course, I had to rip open the book and find the little guy
and sure enough, he was not lying.
There is this little bald guy smoking a pipe on every page
where there is a thin section.
And the reason I am showing you this is to tell you
that if you're not looking for the little guy with the pipe,
you're not going to find it.
So every time you look at anything you have to be ready
to expect everything and especially if you're doing it by remote control
on Mars, you have to make your brain very available to dynamic spinning.
So I'm going to stop yakking here and let you ask some questions
and we'll take some Tweet questions.
And everything is fair game and if I don't know the answer,
you can write me an e-mail
and I promise you I'll try to get you the answer.
It's just pamela.g.conrad@nasa.gov
or you can just Google me and you'll find me.
That's it.
[ Clapping ]
>> I think I read recently they're finding a lot
of fluorine on the surface.
Is that right?
>> Chlorine.
>> Chlorine not fluorine?
>> Okay. But they're saying that that's making it hard to figure
out whether there was life or not.
Is it something with the instrumentation
or just not something you expected?
>> So the question is do we have a lot of chlorine on Mars
that he was reading this.
And so the short answer is yes.
We see chlorine on Mars.
And what happened was when the Phoenix Lander went
and did its 90 day mission,
it detected a material called perchlorate [phonetic].
It's a very reactive material but it typically exists
as a salt stuck onto something else.
Now the thing is if perchlorate is globally distributed,
that means something about the source of volatiles.
You know Mars has volcanoes.
In fact, it is home to the biggest volcano that we observed
in the solar system, Olympus Mons.
And so we know stuff has off gassed from the Martian interior.
So chlorine has been thought for a long time to be one
of the volatile components in the interior of Mars.
And we indeed with Curiosity saw the results of a chemical compound
that contains chlorine and oxygen.
Now we are not saying it is definitively perchlorate
because it's hard to tell at this point.
We have enough chemical evidence
to definitively say it's an oxidized salt of chlorine.
The reason why people point out that this might have a relationship
to our ability to observe not necessarily life
but organic molecules is because when we take something
and we heat it up on Earth and we add oxygen to it, it combusts.
So this is a source of oxygen.
And the way we try to drive off the volatiles
of solid samples is we do something called pyrolysis.
We heat them up to a high temperature.
So the concern was if you have this material called perchlorate on Mars,
would it basically combust or burn anything
that was an organic molecule?
The short answer is we don't know the answer to that yet.
The slightly longer answer is there are lots
of chemical things you can do to determine whether or not the salt
that we see is that or is some other type of chloride or chlorate.
And stay tuned.
Does that answer your question?
>> Yes [inaudible].
>> Okay. Yes?
>> How long did it take the Curiosity Rover get
from Earth to Mars?
>> So the question is how long the commute took
from Cape Kennedy to Gale Crater?
And the answer to that is in time it took 8 and a half months.
And in distance, it was a very modest journey of 354 million miles.
[Chuckles] It's not because we were 354 million miles from Mars
at the time but the actual path that Curiosity took using the gravity
of the different planets
and avoiding other stuff took it on that long journey.
The distance and the time it takes
to get Mars depends upon the relative position
of the planets, of course.
So at different times during Mars and Earth's year,
the journey could be favorable lasting 8 and a half months
or it could be not so great lasting 2 years.
So we hit it at a good time.
And that's why NASA defines what we call launch windows
when the planets are close enough together that you don't have to burn
so much fuel that you would need a humongous rocket to carry
that much fuel to just, you know, get you the right amount
of boost to go into cruise.
Yes?
>> Is there a high risk that something
like an asteroid could come and like disrupt the path of Curiosity
or even take it out like if different rocks coming in?
>> So the question is, is there the possibility
or at least there is a very high likelihood that an asteroid
or something could basically hit Mars and either disrupt the path
of Curiosity or [inaudible]?
And so the short answer to that it's not a very high likelihood.
There are different times in Martian evolution
when there was a lot more activity in that regard.
However, there are recent craters on Mars
and so Mars is still getting hit.
And so are we for that matter.
We recently had an impact that was not so gentle.
And I think that the risk is quite low.
I can't say it's 0 but --
>> Are you monitoring?
>> Are we monitoring space objects?
We're always monitoring space objects but it's very difficult
to detect things that come
in from particular angles and could hit Mars.
That being said, we have two orbital assets from NASA, Mars Odyssey
and Mars Reconnaissance orbiter that take images of the Martian surface.
We can see things like new impacts but seeing it in advance,
Curiosity doesn't move that fast that we could really get
out of the way if we saw something.
[Laughter] Yes.
>> When you talk about terraforming, is there --
how long you would say it would take to create an atmosphere
on Mars using -- say there's ice that you can turn into water vapor.
How the atmosphere would breathe
but to get beyond the 2 percent that's there now maybe provide some
UV protection.
>> So the question is about a concept called terraforming.
There's a popularized concept not just in science fiction but a couple
of astrobiologists, Chris McKay, among them who have advocated
that you could modify the Martian environment
so that it was hospitable to Earth life, making the atmosphere thicker,
possibly allowing liquid water to run on the surface.
So the short answer to your question is I don't have a clue
because what you need to do is
if the atmosphere is presently still escaping or has escaped
because of the lack of magnetic field, because of the lack
of dynamics at the center of the planet, then you'd have to come
up for a mechanism that would make up for that.
The shorter answer is oooh [laughter] because if we did
that to Mars then we would no longer that part of the laboratory
which is a planet created at the same moment
that has followed a different evolutionary path
by which we can look at our own selves.
So I would hate to lose our nearest neighbor holding
up the bathroom mirror so that we can see our own reflection
and figure out how we are evolving differently.
>> But that's the whole point, right?
One day we may need that other planet.
>> I think all organisms explore as a way of looking for opportunities
and threats in their environment.
And at some point, we will explore beyond the Earth
because we have to go.
My thought is that we're not going to go
because destroyed our environment.
We're going to go because we couldn't help it.
So I'm not so worried about that yet.
Yes?
>> There were some other devices placed on Mars.
Are they still operating?
>> The question is about the other assets that have landed on Mars.
Sorry for the NASA speak, I've been there now for enough years
that it just flies out of my mouth.
We call everything that we send on a mission an asset.
The other rovers that are still on Mars now are --
first the Pathfinder Rover which was there in 1998.
It was a little tiny thing, technology demo about this big.
And Spirit and Opportunity which are about this long and about this wide
and about that high, so Opportunity is still sending back data roving.
Spirit got a sore foot and she is no longer actively commissioned
but she's still there.
And so those are still there.
The landed platforms that we have sent --
that is those things that don't have wheels and can't rove,
the two Viking missions from the mid-70s, the Phoenix Lander
that went several years ago, the sad other things
that approached and landed vigorously.
All of these [laughter] are in the same category
of it's a one way ticket because we don't yet know how
to put together a mission with enough resources
to bring something back yet.
And we're working toward that.
It's a very slow process because for one thing,
we have budget constraints.
And for another, the amount of radiation hardening that has
to be done to keep something going for years and years and years
and years is -- requires a lot of development on the front end
and a lot of space qualification before you send it.
So it's a one way ticket for now.
Yeah.
>> How long did it take Curiosity to do one mile?
>> How long did it take Curiosity to move one mile?
So the bad news is we haven't moved a mile yet.
[Laughter] And the reason why is because we are so nerdly
that we have to stop and look at everything on the way.
And so we've moved about 500 meters.
So that's not that far but we're looking at really cool stuff
and we just couldn't help it.
Yes?
>> From what you've learned so far,
what feature of Mars do you think creates the biggest impediment
to life?
>> The biggest impediment to life on Mars.
So that's a really interesting question because right now,
I don't see an impediment that I would considered a showstopper
but if I were to think about life in terms of Earth life,
the thing that I think is really important is to have a diversity
of things you can do chemically.
So until we understand what the diversity
of chemistry is that's taking place on the surface
or in the shallow subsurface,
I won't really know the answer to that question.
But I don't think there's a huge impediment just now.
Yes?
>> What is the impact from Curiosity of [inaudible] temperature changes?
So what's the wear and tear factor that affects the instruments?
How does it do it?
Do you have to have allowances for it and so forth?
>> That's a great question.
He's asking what is the impact of environmental degradation on us not
to mention on the stuff we're measuring?
And so the -- when you develop a piece of hardware and you send it
to another planet, you have to test it
to two times it's nominal lifetime.
So the big impactors are one, radiation, two,
radiation, and three, radiation.
That's a tough one because we have a lot
of microprocessor controlled stuff and it causes a bad thing
to happen called single event upsets which change your registers
and how you retrieve and send data.
So that is a concern but we have radiation hardened materials
as do all spacecraft so we hope we are mitigating against that.
Also sun, ultraviolet light, it's harsh.
And so ultraviolet light is hard on detectors that are CCD
or charged couple device detectors like we have in our point
and shoot cameras and in our cellphones.
They don't like ultraviolet light either.
So beyond that, the mechanical threat always has
to do with thermal cycling.
We get hot.
We get cold.
We get hot.
We get cold.
Every day this happens.
And so over time you just stress materials and they degrade.
So those are the three main things.
>> Wind and blowing sand --
>> Wind and blowing sand is really not that big a factor.
>> [Inaudible] one of the lenses and things like that --
>> That's why we got those lens covers.
And don't forget to take them off before you take the image.
[Laughter]
>> We'll take one more question
and then she'll take questions afterwards.
>> So since, you know, as you said it's a one way ticket whenever you
have a Mars exploration project but you can --
you're able to gather data from most of the other rovers you've sent
for many years after their official mission span.
How long do you think past -- you know how long will Curiosity last?
>> Oh that's bad.
That's like trying to predict how long somebody's marriage is going
to last.
[Laughter] So the short answer is this thing is just amazing.
I can't believe how fabulous it is that we're there
and that we're working after all those years preparing.
If Spirit and Opportunity were designed to last 90 days
and that was in 2004 that they landed.
You can see that there is a good return on investment.
I am not going to fall into the trap
of guessing how long Curiosity will last
and the return on that investment.
All I can say is that I hope that if things move in a scaler way compared
to Spirit and Opportunity that it'll be my day to go
out in a pine box before Spirit -- Curiosity is done but I don't want
to say that either [knocking] because [laughter] there's lots
of stuff in the environment.
But anyway, I think a long time.
>> Thank you again.
>> My pleasure.
[ Clapping ]
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