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Who would love to leave this planet?
Raise your hand.
Wow, that's a lot.
Luckily, is there some opportunities
coming up, this
Mars One where you can
go to Mars but without
a return ticket?
And who applied for this one?
Do we have any applicants for Mars One in
the whole world?
More than we expected.
Just three, four.
So just a few of brave.
But recently, also, SpaceX announced
their detailed technical plans on how to
get to Mars and their technical
plans for the vehicle, who has seen
the announcement raise your hands?
Yes, quite some
people are informed since we already
know three or four people who would go
to Mars without coming back, who would
trust his life to Elon Musk
and go up there with him.
Some more, some more.
Yeah, I definitely see a colony up there.
OK, by the way, what's the difference
between the Berlin airport and Mars?
Humans will land on Mars in the
foreseeable future.
So next talk is not only about MS.
It's about the three thousand
five hundred eighteen known exoplanets
and how to pick the right one for
civilization attempt.
And we'll also learn about how to get
there and what technology you need for
the research, because as we know,
it's not about the target, it's about the
journey.
Liz George and Peter Roskam, who have
both provided us with food for thought on
prior to three events,
are now here for us on this stage.
They have many things in common.
They are both instrument builders for
astrophysics.
They both work at the Max Planck
Institute for Extraterrestrial Physics,
and they are both working in the same
infrared group.
And on top of that, they both developed
some of the world's most sensitive
instruments.
Please take us with you on
a journey through space,
Liz and Peter.
So hi, everybody.
It's great to be here.
I think this is by far the biggest
audience that either of us has ever
spoken in front of this one.
The biggest one.
The biggest one. So thanks for coming
out.
So today, we want to tell you about
interplanetary colonization and by
extension, interstellar colonization,
which is much harder.
So we'll start out with the question, why
leave Earth first?
It's a pretty great place, right?
So this is our home planet.
It is about 70 percent
surface area covered in water, as you
heard in the last talk.
It's got a convenient 1g of gravity,
one part of atmospheric pressure.
The atmosphere is about 20 percent
oxygen.
And don't forget the most important part.
Oh, yeah. It's the only planet we know of
that has Wi-Fi.
So Earth
is pretty great.
Why leave it?
And we can start with analyzing
the past history of Earth, namely
that Earth hasn't always been such a
great place to live.
So this is the fraction of species
to go extinct in each
time interval as a function of time.
So this goes back about five hundred and
fifty million years.
And there's a lot of space on this
planet, five of which are known as
the Big Five Extinction events.
And you may have heard of some of these,
one of which the most
latest one here is when all
of the dinosaurs were wiped off of the
planet.
So something else you might not know of
is that we're, in fact, in the middle of
the sixth big extinction event
on our planet where we're losing species
at a rate a thousand times above the
background.
So we can ask
ourselves what has caused these
extinction events in our history.
There's many things. So the first big
extinction event was because we actually
had too much oxygen.
Extinctions also happened due to too
little oxygen, volcanoes,
sea level changes, global warming,
global cooling,
giant meteors hitting the earth and
most recently, human activity.
OK, so you can say you
were actually much more advanced than the
dinosaurs, we have technology
in principle, we should be able to
survive any of these planet, altering
potential extinction, causing events that
come our way.
But actually, in the very long term,
we have a bigger problem and
that is our son.
So eventually our son will
use up all of its hydrogen fuel
and balloon up into a red giant.
So first, all of the water will boil
off of the earth.
That won't be pleasant for anyone.
And then eventually the star will grow so
large that it actually envelops the earth
inside of the star and completely
freeze the planet.
So given that this is C.C.C.,
you can think of it as making
an off site backup of humanity before
your server room burns down, which
in this case and in the cloud and beyond.
Yes, in this case, we know it
will. So we actually have a pretty strong
motive here to get off of our planet
in the foreseeable future.
So that brings us to our next question,
namely, where are we going?
So all of you in the audience and
our previous speakers
have talked about Mars, and
we also want to know how we learn about
our new home.
So this is what Mars looks like from
space.
And you can think this is a good target
for us. It's relatively close in terms
of interstellar space if you
want to get an idea of distances.
Stick around for the last talk in this
track about how space really is
huge.
And you heard from John Warner.
It'll take about two years round trip
there and back.
So Mars also has an atmosphere,
but it's very thin, mostly CO2.
It doesn't have a magnetic field.
So it's constantly bombarded by
cosmic rays and solar wind.
So this essentially sterilizes the
surface and means that humans would have
to live underground.
It's also pretty cold there.
So while Mars is close
and technically is in the habitable zone
of our sun, meaning there's can be liquid
water on the surface, it's
not actually that comfy of a place to
live.
Another target that people talk about is
Europa. So this is one of the moons
of Jupiter. There's several of them.
And this has been
a very interesting target because
it's actually an ocean world.
So the entire moon is covered in water
with a very hard, thick
ice shell on the outside.
And conveniently, it also has an
atmosphere of almost pure oxygen.
So you think, great, it's got an ocean,
it's got oxygen.
What more could we want?
Unfortunately, the average temperature on
the surface is so cold that the ISIS
is hard as granite and you'll have to
drill through 15 kilometers of it before
you get to the ocean.
It's also sitting in Jupiter's
radiation belts. So the radiation
intensity on the surface is so high that
a human would die in less than 12 hours.
So also not so pleasant.
And also the monolith tells us not to
them.
That's true.
OK, but the really interesting thing is
these planets are close and we actually
know an extraordinary amount about them.
And the question is, how do we know these
things?
So in our solar system, we
can actually send satellites to orbit the
planets and landers that
sometimes crash, but sometimes
actually land there and give us some
information.
So this is a picture of
a mountain. It's Mount Sharp on Mars, and
it's actually taken by the Curiosity
rover that is sitting there on the planet
right now taking data.
So this is a selfie curiosity
took of itself.
And one of the really cool things about
curiosity is it's got a giant laser on it
that it uses to actually vaporize the
rocks and analyze them.
So we have this probe sitting there, and
this is the first spectrum to come out of
this rock vaporizing laser
measurement device.
And what you can see here is a
whole bunch of spikes in the spectrum.
And each of those, if you have
some very good chemists back home,
can be matched to different
elements. And so you can see our soil
on Mars has iron, magnesium, silicon,
aluminum, calcium, et cetera,
all things that would be very useful to
say potential habitants of Mars
or just in general to know about
what kind of life could live on Mars.
So you are essentially saying we
are safe and growing potatoes now?
Yeah, we could grow potatoes in this,
for example.
OK, so again,
this brings us back to our previous
problem, though, of the sun is eventually
going to envelop the Earth and make Mars
a hellish desert world.
So we've got to go a little
bit farther than Mars.
And that brings us
to exoplanets, so this is
a graph of the exoplanet detections
per year since the 1980s,
and you can see, you know, 30 years
ago we didn't even know that there were
other planets in the universe other than
in our solar system.
And in the last several years, we've
really learned about an explosive growth
of exoplanets while they were there all
along. But our detection technologies got
better and they're detected in many
different ways. But today, I'm just going
to tell you about two different ways.
They detected the radio velocity
and the transmitting method since most of
our exoplanets were detected that way.
OK, so the first thing you should know
is that a planet doesn't orbit a star,
so rather a planet in a star.
Both orbit the common center of mass
between the system.
So in this graph, you see the big thing
is the star, the little things, the
planet and the star is wiggling back and
forth.
And what this means is as
if you're observing the star as it moves
back and forth. The light is Doppler
shifted throughout the orbit.
And what you get is you get slightly
blue, shifted light on one part of the
orbit and red shifted light on the other
side.
And if you observe it for a very long
time, what you see is a periodic
signal and you can analyze this periodic
signal to learn about the mass of the
planet that's orbiting how long the
planets here is and how far it is from
the star.
So this is a this is a very precise
way to detect planets, but you need an
extremely precise spectrograph.
And this has been done in different ways
over the years.
Early attempts used vats of boiling
hydrofluoric acid to calibrate the
spectrograph wasn't so great for the
instrumentation.
These days, people use laser combs.
Stick around for the next talk if you
want to learn about lasers.
So the other way that we detect
exoplanets is the transiting method.
So this is the method used by the Kepler
spacecraft. And basically what you do is
you stare at a whole bunch of stars
for years and you wait for
the planet to go in front of the star
and you would see a very slight dip
in the brightness that
will change over time.
And an earth like transit
of a planet lasts about 13 hours
and happens once a year.
So on average, need for these transits to
define an orbit.
And so it takes many
years of observing before you get the
exoplanets.
So what you get from this, in contrast
to the previous method where you get the
mass of the planet, you get the radius of
the planets, you know how big it is.
But since you have no idea what it's made
of and how dense it is, you don't know
how much it weighs.
But what you can find from the system, if
you know about your star,
how much light it outputs, is you can
define a habitable zone where the surface
of your planet could have liquid water.
And what you can do is you can take the
orbit and the size and you can get a good
idea of roughly what the planet's
system looks like and whether the planet
is in the habitable zone.
So this is an example of the first
roughly earth sized planet located in the
habitable zone of a red dwarf.
And the reason the orbit is smaller
in comparison to our solar system.
So this is the F orbit
and that's roughly comparable to the
orbit of Mercury is because the Red Dwarf
star is dimmer.
But that brings us to the next question.
OK, so we know it's a roughly earth size
planet and it's sitting in the habitable
zone, but does it ever breathable
atmosphere?
Does it have a greenhouse effect that
might make it warmer?
How do we find this out?
And the problem
with studying planets around other stars
is that they're super faint.
So there's actually a planet in this
image.
And if I hadn't put this label here, you
probably wouldn't be able to tell where
it is.
And in fact, this is a planet that's
sitting super far out from its star.
It's way past the orbit of even
Neptune.
And if you wanted to observe as an
Earth like orbit, it would be way in
here.
And it's roughly a factor of a million
fainter than the stars. So digging out
the signal from behind the star is
extremely hard.
And one thing you should know about
telescopes is that the bigger they
are, the smaller this diffraction pattern
is. So if you make a bigger telescope,
you concentrate the starlight closer
in and in principle you can see these
smaller orbits.
So this here is
the Kepler satellite.
That is what has actually detected most
of our exoplanets in the universe
that we know of so far.
And soon NASA will
be launching GBW.
It's a factor of roughly six figure.
So that's great.
And actually, the Europeans are
planning to build something called the
extremely large telescope.
Not a joke, that's actually the name,
but it will have a thirty nine meter
dish. And this will enable us to
directly study exoplanet
atmospheres with the hope being
determining whether any of these
habitable planets actually have
an atmosphere that would be conducive to
humans colonizing the planet.
So I'll end my section
with the Kepler ORAY here.
And this is all of the known exoplanets
from the Kepler mission
in their orbits
to scale. So the bigger planets are
Jupiter sized and the small ones are
size.
And if you want to learn more about all
of the worlds that we know of outside
of our solar system, you can go check it
out. On NASA's website, they have
something called the New World's Atlas,
where you can learn about each and every
one of these exoplanets.
So with that, I'm going to hand it over
to Peter, who's going to cover how we get
there. All right.
Yeah, how do we get there?
This is actually far from easy.
Do you know the first rule
of space club is it don't
talk about Space Club now.
It's space does not cooperate.
We learned this from Mark Watney,
meaning if you do anything with space,
better know really what you're doing.
As a rule of thumb, you should be
treating vacuum like a poisonous
gas that's about gets it right
and then you can start building
things.
Actually, there's a second rule of space
club.
Don't talk about Space Club, no, be
prepared
to quote Mark Watney again.
Yeah, exactly.
Um, and these are just some of
the topics you want to maybe
think about. It's not just about should
we go at all?
And if how should we colonize?
Should we send robots?
What propulsion.
Propulsion is the right one.
Do we need planetary bases on the way?
What is actually the sociological
aspects?
Do we get along on those spacecrafts
for many, many years in confined
space?
I don't know. Would my husband get on a
spaceship with me for four years?
So meaning you have to plan your trip
carefully.
This is nothing new, even if you do
something within our solar system,
you have to plan your trip carefully.
People have done this before.
Well, obviously, we have sent
probes to the inner planets,
to the outer planets before.
And the first concepts
date back to the beginning of the
20th century.
This is actually the way, for
example, how do you how you want
to get from Earth to Mars fuel
efficient? It's a so-called human
transfer orbit.
So you start from Earth, which is
the blue planet, in the
position where it is, where the blue
field circle is
shown on the slide.
At the same time, when you start is in
the position where the open
circle is. But by the time you have then
traversed on your home and transfer orbit
towards the Mars orbit,
Mars would be in the right position that
you can actually just land on Mars
if you have more time on your hands,
if you want to use even less fuel.
There are other options we've just seen
in the previous talk and heard about
Rosetta and Rosetta did
several swing bias and gravity
assisted flybys by other planetary
bodies in our solar system,
using those to then accelerate,
get into a different direction without
using any propulsion.
And actually since a couple of years,
there's another method
which I encourage everybody
who was interested in this to just Google
and look up. This is the interplanetary
superhighway, as it is called.
This is a system of how you get
from Lagrange points to other Lagrange
points in our solar system
without any fuel.
Essentially, you just have to get
onto those tubes, which are in
my speech, I guess, open and close many
folds. I'm not a mathematician, but
this is what you want to look
up and then you can just coast along
these lines through our solar system.
But normally you want it fast.
You mean like one of those space X
rocket?
Well, sort of. Um, so
space X is fine for Mars?
Definitely.
These are chemical rockets.
You can still tweak them a bit.
But if you really want to go far out in
the solar system or then even talk
about Interstellar, then you have to use
other methods of propulsion.
Um, let's look
at these very crazy
spacecrafts for interplanetary
missions which have been proposed before.
You will see these designs
a lot. If you start looking
into
spacecraft design, it almost always
looks like this.
So there is at the very front
that is the payload, which could be
some crew compartment.
If you want to send humans, it could be
some cargo which you want
to send to an otter colony,
maybe in the in the
asteroid belt or to the moons
of of Saturn.
Um, the big thingee
behind it, this is not wings.
I mean, we don't need wings in space, but
we need to get rid of a lot
of excess heat that gets created by our
nuclear reactor, which is
at the very real for a spacecraft.
So these are radiators.
And since space is essentially
black and really cold, I mean, it's
two point four Kelvin point
three point five.
She's the expert.
Oh, we can efficiently
irradiate
hot stuff away using a so-called
radiators at the very end, a set that
is a nuclear reactor.
Of course, there are some things like ion
engines and whatnot.
But I want to highlight one of these
crazy ideas, and this is how the reactor
actually looks like a sufficient fragment
rocket engine.
What you see is like in a in
a in a reactor, you
might know it has some
nuclear stuff in the middle
here shown in green.
And of course, there's a moderator around
it to get the neutrons to the correct
speed. What is the interesting
part here is that you actually
will use the propellant itself.
So the plutonium carbide
dust confined with
superconducting reflector magnets
to get the efficient particles
out and get some radiation to the
to your back. Of course, the particles
have to be charged for that.
So gamma radiation will go in the other
direction and you better have some
shielding because otherwise you are
frying your crew.
The fission fragments are pretty fast.
They go at almost two
percent, the speed of
light. And we also get a ton of energy
out of it to power thermo
electric generators, to have excess heat,
to get electricity on our ship.
If you want to go to Interstellar.
This is not going to cut it.
We have to have high specific
impulse and high thrust.
So we'll talk about briefly about
Project Orion. This is a complete
different Orion than the
next.
This is the old project I ran out,
Project Orion,
not to be confused with Project Pluto.
Don't look at Project Pluto.
This is this is insane stuff.
And after 10 clicks on the intercepts,
believe me, I know what I'm talking
about. I'm from Bielefeld.
You end up in a swamp of conspiracy
theories. Don't go there.
Don't. OK,
so this is Project Orion, which
is essentially nuke us to the stars.
We have a payload section again at the
very tip of the ship.
We have a propellant magazine
and then we have a shock absorber
at the very end.
What we do well, we take some nukes,
which we have in our compartment, just
throw them out of the rear,
have to make boom and then propel
our ship forward.
I would like to point out that this is, I
think, the most reasonable use of nukes.
So it would be perfect
we use of our nukes today.
Of course, you may be do not want to
have this on your surface
body. Maybe if you want to start from
Earth or from Moon or from Mars because,
well, your mates who stay in the
lunar base also will essentially be fried
because of your nuclear explosion.
So do this in free space where there was
nobody else and see that there's nobody
tailgating you or something.
Watch out.
Are there other options?
Yes, there are other options and said
there are these ion engines, which are
very nice engines, they are being flown
on spacecrafts right now that
you use an electric field to accelerate
ions.
It's only a tiny bit of thrust, but
it's very, very efficient.
And if you have a long mission duration
and you can just I mean, a rocket, for
example, like the Saturn five,
there's a space shuttle, they go for some
minutes. But if you have an engine that
can just power you
your craft for four years, you
will get faster in the end
about laser propulsion.
We will talk in the next talk
at the very beginning.
And all the other things will not
talk about because as I said, you get
into a swamp of conspiracy really
fast.
Don't look at them drives.
Just don't do it. OK,
the fairy dust would actually be some of
the torch ships.
Torch ships classify it as normally
constant acceleration engines.
And this could bring you to the stars
pretty fast. But we have no idea
whatsoever what technology to
use in constant acceleration drives.
So if you're going fast,
you have to have your shields up.
Believe me, if you are going
at 20 percent the speed of light in
the end or something like that,
you have to
make sure that you understand that space
is not empty. Space looks like this.
So this means there's a ton
of stuff between the stars, the
interstellar medium, its neutral
atoms, charged atoms, molecules,
dust.
And if you could do a quick calculation,
you will see that if you, for example,
that go at a speed of 20 percent,
the speed of light, you will erode
one centimeter of aluminum in front
of your ship each year just
from the interstellar dust.
So this is something you really should
pay attention to.
Of course, there are other things
also floating around micrometeorites,
although they are not that frequent
in interstellar space.
Of course, it's also something we have
dealt with before with interplanetary
missions, with
Earth Moon missions, with other
things in Earth orbit.
And this is, for example, how it looks
like this is a famous so-called wippel
sheet on the
on the left. So you essentially have a
sheet of metal in front of it, which
absorbs the first impact.
And then you just have a spray of debris
from your impactor on your actual
spacecraft. Or you could do something
like metal forms or something.
This is actual research being done
right now. So, yeah, we are preparing
for that.
But of course we want to have really
nice things maybe.
And then yeah, it's BYOB,
bring your own magnetosphere or
forcefield and
yeah, if you, for example, just put a
magnetic field around your ship, you
could collect plasma on the
way, have a nice plasma in front of you,
and that would lead to having a nice
magnetosphere around your ship which
would then deflect charged particles.
Never forget what is behind you
because your own reactor is trying to
kill you all the time.
And that's actually why this thing
has this weird shape.
This is not because the artist thought
this looks nice. No, because this is
the deadly radiation.
And actually, well, it's a it's a
cone around your ship.
So when you turn your ship over, because
we have accelerated for 20 years in the
one direction and you turn it over at the
middle of the trip, accelerate in the
other direction because you want to
decelerate.
Well, there should be nobody sitting
in front of you because
you're pointing in that direction.
The particles are still fine.
You will not get your own particles,
but everybody is in front of you will
then get the full radioactive blast.
So maybe point your ship slightly off
of the planet you want to land on.
Yeah, maybe.
Yeah.
So still with all
of this is the only option of going
really fast are so-called
torch ships constant acceleration drives
which could bring us to Proxima Centauri
in about OK,
seven to eight ship time.
Earth time would be about 10 years
because relativistic effects will then
come into play anyway.
It will take long.
It will take so long that you better take
a nap during the voyage.
And this might seem a bit like
science fiction, but actually this is
research that is being done by
medical researchers
at NASA. It's private companies
right now and these are these
artists impression hibernation
could be an option.
It's not.
Routinely used for people who have had
severe accidents, you just cool the
people down and actually if you, for
example, cool down your body temperature
from 37 degrees Celsius to
32 degrees Celsius, you're reducing your
metabolic rate by 70 percent.
And this means, well, you don't have to
bring a lot of
water, food, water, food,
oxygen on your ship.
Um, last thing.
No, this is not space.
Sorry, this is not an option.
This is no option at all in
space. There are so many things
which have to work over a so
long period of time that we actually, for
some of those have no idea how to
accomplish this.
We're talking about trip times of around
100 years, maybe so
I have not seen a computer that
has worked continuously for 100 hundred
years, neither a propulsion
system, electronic system.
So if you have such a ship,
you better bring all the spare parts
and you have two ships or you have
maybe capabilities on board
to do this, like
mining asteroids to get new parts
for your shield, which has eroded away.
Maybe that, um,
but this is not to scare you away.
This is just the challenges.
I mean, we have we have done other
things. Mankind has landed people on
the moon.
Soon there will be Mars.
And please keep in mind,
there's is a very famous quote by
the father of rocketry,
Ziolkowski, and this is the Earth.
Is the cradle of humanity, but no one.
Lives in a cradle forever.
So at some
point we'll get out there.
The question is when?
But there's a lot of stuff to do and
you're all invited to take part in
it. Thank you.
We have some time for questions
left, so please go to the microphones
if you have a question and remember
to keep it as brief as possible.
Signal Angel, please give us the
questions from the Internet.
That's one question from the Internet
if you assume
Emtriva will work and will
have usable thrust.
How would that change the space travel?
Could we start could be shot
in the path instead of relying
on parabolas?
Good question. Next question.
Microphone one.
If we have magic, then everything is
fine. Yes.
I have a question that has always
bothered me with space travel.
And that's basically what's the rationale
behind aiming for a foreign
and faraway planet that right
now is basically an utter wasteland
and hostile wasteland.
And instead of finally
getting our shit together as a species
like surviving on the planet that we were
literally, literally made for by nature,
why should we survive when any,
like natural wasteland if we
can do it here?
Well, if you remember
earlier, there was
the problem that our sun is eventually
going to expand and consume the Earth.
Yeah, but that's like we are far,
far away.
Yes. I'm not advocating for us not
getting our shit together.
We should definitely do that.
But in the very long term, human space
exploration is a necessity.
And so we should always keep
our eyes on the future of our species
in general.
So we're not.
One last question.
Microphone four, please think
again, you think the alcubierre drive
will change everything?
Well, it's a nice mathematical concept,
but the
the stuff you need to make it real is
it's not even clear if it's physics,
physical reality.
Yes. If we have a warp drive, it's fine.
Yes.
But sorry,
it's not it's not going to
happen within our lifetimes, I promise
you.
So if you manage to build a warp drive by
the end of Congress, we take zolta with
us.
OK, so one more thing is that
we've planned for this space track
speakers to congregate
shortly after midnight at the speakers so
far outside of Sol G.
So if you all have more questions for us
that you'd like to ask later, shortly
after midnight, that's where we'll be.
All right. Thank you.
Thank you very much.
So that was Liz George and Peter Bush
camp. Thanks.