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In this part, we're going to learn about resources in space.

Our learning goals are to recognize that near Earth locations,

particularly asteroids, that can come close to the Earth,

represent extraordinarily valuable resources for minerals and metals.

And as the Earth runs out of these resources, we may turn to the space

environment to replenish these important components of our modern civilization.

We'll also recognize that the solar system is also the source of many minerals and

chemicals.

And also substantial amounts of liquid water,

which would be the basis of living beyond the Earth.

Finally, we'll look at the extraordinary success in

understanding the possibility of biology beyond the Earth from spacecraft that

have conducted synthesis of Earth-like planets in the nearby universe.

This is an asteroid, and

we have the technology with spacecraft to take a near Earth asteroid to tethered

on it we've actually rendezvous with several comets and asteroids so far.

And potentially attach rockets to it and steer it into an Earth captured orbit.

There are asteroids most of which live between the orbits of Mars and

Jupiter that do venture close to the Earth.

And by taking a particularly metal rich asteroid, perhaps half a kilometer across.

Attaching rockets to it and steering it into an Earth captured orbit,

we would have an almost infinite resource for minerals, chemicals, and rare Earths.

So this is a way within a human life time

we may be able to start harnessing the resources of space.

It sounds like science fiction but it's not.

None of the technologies involved are beyond our purview.

Here, you can see that the cost and especially the projected cost

of terrestrial resources of various valuable kinds for

our modern civilization are going up due to the scarcity value.

Also because many of these resources are found in unstable or politically

dangerous parts of the world, where we don't have access to the resources.

Meanwhile the cost of retrieving those resources from an asteroid goes down

as our technology improves.

So clearly,

we're not too far away from the prospect of being able to boost the world economy.

And our ability to manage our lives on the Earth by using resources from off Earth.

The economic demand for these materials fills many types of markets on the Earth,

our electronics industry, our transportation industry.

We also need life support and propellants to work in space, and

they can come from asteroids.

Fuel cells, things that are an important part of our future energy economy,

they can come from asteroids.

Some things like rare Earths,

are extremely important in a semiconductor industry and they have very high value.

Obviously, metals, platinum group metals, gold, silver, platinum,

those also are valuable, in not just jewellery, putting cars,

and in many parts of industry.

So there are a number of materials where asteroids are valuable.

These materials can come in many forms.

Sometimes a material like water would actually be used locally.

We can get water not only from asteroids but from the Moon and

Mars to sustain human habitation beyond Europe,

which is much cheaper than bringing that up from the Earth.

So for living and

working in space, we want to have as much locally source material as possible.

For construction, for breathing air, for making rocket fuel, and for living.

Economist and politicians have started to dig into what kind of an economy this

might be, based on space resources.

And putting all the pieces together, it's potentially a trillion dollar industry.

A significant fraction of the world GDP.

This isn't going to happen over night, and it's risky.

People will gain and lose fortunes trying to mine asteroids.

But so they did when they moved out over the American West looking for

minerals like gold or looking for oil in Texas, it's the same thing.

It's a risky endeavor, but some people will do it and

some people will succeed at it.

So I think it's part of our future economy.

Moving beyond the Earth,

there are places where the raw materials we might need to survive exist.

The core ingredient is water.

It's impossible to live without water.

Humans are two-thirds water by weight.

And so we may think some of these places out in space like the Moon and

Mars seem very dry and arid, but they are actually not.

These are images of Mars from orbiters from the 1970s, and

these images to a geologist, and this one is even obvious, looks like a river delta.

These looks like alluvial plains caused by deposition or sedimentation.

So although Mars doesn't have water on it presently because it's too cold and

dry, the atmosphere's too thin.

There's ample evidence that Mars was warmer and wetter in the past.

In fact, there's very good evidence that Mars had shallow seas two or

three billion years ago.

And it even still might have water underground.

Here's a pair of images taken by an orbiter less than four years apart.

And you can see there on the edge of this escarpment

in some part of this period of time, a new channel has been curved.

Now the people who studied this wonder whether it might just be caused by

gravel or sand rolling down a hillside.

But you can only actually produce this by a liquid rolling down.

And it's likely that what happened is that there's a subsurface aquifer which Mars,

we think has many, that erupts through the edge of an escarpment and

erodes a channel.

The water then evaporates into space very quickly, but

it's pretty good evidence that under the surface there's water on Mars.

And if there's water on Mars, then we have the potential to sustain life on Mars.

And in fact, life may already exist in Mars on microbial form underground.

This is a world unfamiliar to most people, in the outer solar system.

It's Europa, one of the moons of Jupiter, one of the Galilean moons,

the first four to be discovered.

And the features you see are ice cracks, this is an icy ocean.

The entire world is covered in water and on top of that ice,

hundreds of meters thick.

Even the Earth, it's only covered by water three quarters.

This is an even more watery world than the Earth.

Smallest features you can see are about the size of a football field.

And there's evidence in imaging taken over the years that these ice field are heaving

and growing and cracking.

No water can escape, because again very far from the sun, far too cold for

liquid water to exist on the surface.

But pretty clear, if you make a model of this moon,

that there are liquid oceans kilometers deep all around this moon.

It's a compelling target for exploration in the outer solar system.

And again if there's liquid water there and some energy,

that could be biology as well.

And there are surprises.

In our exploration of the solar system, we found probably a dozen worlds,

mostly moons of the dying outer planets that have water.

In every case that water is underground, usually under a cap of ice and

rock mixed together.

But the big surprise a decade or so ago is Enceladus, a tiny moon of Saturn.

It's smaller than Rhode Island,

it was not of much interest to planetary scientists because it's so small.

And yet the Cassini mission saw icy geysers spouting ice particles

into space from fissures on the surface of this tiny moon.

And modelling of this moon, suggest that there's liquid water,

kept liquid by pressure and also by tidal forces.

The moon being squeezed by its parent planet, that forced the water to come

out and immediately turn into tiny ice crystals as it shoots into space.

So even this tiny world unnoticed and unconcerning to planetary

scientist until this discovery, could have the potential for biology.

So both the inner and the outer solar system have places that are potentially

interesting to host biology, and

the places where humans could potentially one day live and work.

The field of astrobiology is the study of life in the universe, and

in anticipation of the discovery of life beyond the Earth.

Because as we speak, there is only one place in the universe we know of with

life, and we're standing on it.

Biologist and astronomers are fairly confident that life in the universe exist

and it may be quite abundant.

This evidence comes from several lines of of reasoning.

The first that the simple organic ingredient of life forming naturally and

easily in laboratory conditions.

Nobody is ever made a single cell in the lab and

actually only small fragments of DNA and RNA, the building blocks of life.

But they form naturally from the very simplest molecules.

We also know that life started on the Earth roughly 4

billion years ago when the Earth was a very inhospitable place.

It formed almost as soon as it could, as you could imagine it forming.

And we also know that life survive not only in hospitable condition of 4 billion

years ago, but continues to survive in seemingly impossible conditions.

Life can exist below the freezing points of water and

above it's boiling point in pressures of hundreds of atmospheres and

pressures of 1% of the surface atmosphere of the Earth.

It can exist in PHs ranging from battery acid all the way upto sulphuric acid,

incredible range of toxicity.

Life can metabolise metals like cadmium, and lead, and

mercury that are compleately toxic to us.

So microbial life is extraordinarily robust, and

therefore we expect it to be robust and abundant elsewhere in the universe.

The new components of this argument have come from astronomy.

From the fact that we now know that the ingredients for

life are widely distributed through space.

The carbon that is a basis of our life form exists throughout the universe.

Carbon has been detected at distances of 12,

13 billion light years from the Earth and distant galaxies.

Chemistry is universal, that's the lesson of astronomy.

We've also learned more recently that the planets and

moons that could host life are abundant.

And just in the last few years, we've actually put numbers on this, and

that's what I want to talk about now.

The existence of habitable real estate in the nearby universe.

And project those numbers for you into the galaxy as a whole.

This is the extraordinary success, and the detection of exoplanets or

planets around other star systems.

Before 1995, we knew of no planets around any other star.

Although people had speculated for centuries and have been looking hard for

decades.

After a stunning success in 1995, the flood gates have steadily opened.

And you can see in the progression for 25 years, a slow decline or

an improvement in the minimum mass of planet that can be detected.

Those first exoplanets were the size or mass of Jupiter.

The ones that are being found now are Earth size or mass or even smaller.

And also the number of those planets that are being discovered has increased

every year.

An extraordinary success to the point where we're now detecting essentially

clones of the Earth at distances of hundreds of light years.

This represents the extraordinary success of the Kepler mission.

NASA's one meter telescope now pretty much finished it's primary mission.

And shows how over the last few years,

the Kepler mission has found literally thousands of planets.

The census of confirmed exoplanets is now over 4,000, even five years

ago the number were just a few hundred, increase of a factor of 10 in a few years.

And most of those planets are small, they're not all Earth size.

Some are what are called super-Earth of a few times the Earth's mass.

And some are like Uranus or Neptune, 10, 15, 20 times the Earth's mass.

But this is an extraordinary success in astronomy and

has put new focus on the issue of life in the universe.

Here's how the Kepler planets divide by size.

So you can see even a handful that are Mars mass or size,

here are the Earth-like planets.

These are super-Earths.

Here are Neptune or just smaller.

Then the Neptunes, and here like the gas giants.

So you can read across to see 200 fully Earth-like

planets have been found in the last few years.

The super-Earth, another 6 or 700 are also potentially habitable.

In other words, could host biology.

So the raw material real estate of just this nearby universe survey of over

1,000 potentially habitable planets.

And before, ten years ago, none were known.

This has all happened mostly because of this one mission, the Kepler mission.

With this data, we can start to fill in the real estate of planet size against

orbital period, to hone in on things that are the most like the Earth.

And these are the percentages of planets found or

particular combinations of size and period of around suns like the star.

So the most most Earth-like situation,

you can see that the percentages of fraction of a percent.

And the Earth size range or super-Earth are 3, 4, 6, 7%, and

you add all those percentages together, and you come up with 50 or 60%.

In other words, a half of all sun-like stars have an Earth or

super-Earth like planets around them.

Earth is not rare in the universe.

Now we'd love to fill in this box here.

This is the box for Earth clones, because these are planets that are the mass or

size of the Earth and have periods of a year, and so are in the habitable zone.

The distance from their star where water can be liquid on the surface.

Kepler hasn't put a firm number on this yet.

But you can see from the adjacent properties that the number of Earth clones

with a fraction of all sun-like stars that have true clones of the Earth is likely to

be a few percent.

A few percent sounds like a small number, but

there are enormous number of sun-like stars in the galaxy.

So let's get a sense of that.

The number of truly Earth-like planet perhaps 250 in total,

would be if you deep your wet finger in some sand,

the number of sand grains that would stick to your finger.

I want to give you a sense of the numbers, astronomers deal with huge number and

they become hard to intuit, so let's use the analogy of grains of sand.

So here the number of Earth-like planets and

most of those are in the immediate neighborhood of the sun.

Kepler targets are typically a few hundred light years away.

The galaxy is 100,000 light years across.

But arm with this data, we can extrapolate to the entire Milky Way galaxy,

the star system we live in that has roughly 300 billion stars.

And to keep with the analogy grains of sand,

that speculation amounts to 10 billion habitable worlds

fully Earth-like in their habitable zones where liquid water could exist and so

biology could exist in the Milky Way galaxy with the ingredients for life.

And a billionaire so close to Earth and all their properties that they're

indistinguishable, they're truly Earth clones.

And that's like the number of grains of sand in the entire sand pit,

that's an extraordinary success.

In this next little animation, we'll just imagine we could visit this worlds.

We can't, the spacecraft we have only let us measure their size,

their mass, and their orbital period.

That's about all, we're just counting them.

But if we could visit them, we'd love to see what they look like.

Are they desert worlds, large tropical worlds, do they have microbes on them,

no life, complex life like us?

We have no idea, that's very hard information to get.

So you're going to see a travel log that last about a minute, where you look at

about a dozen of these worlds to get a sense of them and their range.

If we were to do that travel log and somehow imagine we could travel through

the entire galaxy and look at all those habitable worlds.

You'd be watching that little travel log for about 5,000 years

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When I say Earth clone, I don't mean exactly like the Earth.

There's not ever going to be a complete twin of the Earth in all aspects,

especially down to humans and the creatures,

the same species we have on this planet.

Earth 2.0 is going to look subtly and significantly different from the Earth.

But it still may have breathable air, and it might be habitable.

Those differences maybe very interesting to us.

And I have some bad news for people who think we might be able to move to this

planet we find, the nearest Earth clone.

The bad news is that the nearest Earth clone is likely to be 30 or

40 light years away.

Now that's several 100 trillion miles.

Remember, that we've only sent humans to moon, and

that is a quarter of a million miles.

So we're talking about going millions of times further than humans have ever

travelled just to get to the nearest Earth clone.

So the presence of Earth clones adding space all that wonderful

unused real estate, all those wonderful resources, places we could spread out and

live, in a more leisurely situation.

That doesn't obviate a necessity of taking care of Earth 1.0,

which we're not doing a very good job at.

So it's a lesson for us that habitable real estate exists, but

habitability could be altered by humans, by their own hand,

by technology, by not taking care of the planet.

At the moment, I think we sit on a knife edge, but we still have the choice.

We have the power to go in the good or the bad direction,

but I don't know if we have the where withal to make sensible decisions.

And although it's a little ominous, I'll leave you at the end of this section

with the thought that we get to choose whether we get the nightmare or the dream.

That's the end of this section, and I'll see you in the next video.

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Lecture 9b - Resources in space

Biosphere 2 Science for the Future of Our Planet

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