Speaker 1: At the start of a new millennium. We're about to
embark on the greatest adventure of all time. Five hundred
million miles from Earth, a spacecraft will land on Jupiter's
icy moon Europa its mission to search for alien life.
As we reach out across the galaxy, our spacecraft will
explore the most extreme environments to answer the ultimate question,
are we alone? Our universe is made up of countless galaxies,
each teeming with billions of stars like our Sun orbiting
around them. Maybe billions of planets. Any Earth like planet
could be home to an intelligent alien trying to communicate
with us.
Speaker 2: The Pentagon admitted just moments ago that a researcher at
the Seti Institute in California has detected a radio signal
from beyond the Solar System.
Speaker 3: Deep space Metal de Madrid send Extra Terrestriya.
Speaker 4: Danta Tinti and Ja Khatinti Chanhashenbugga tin Lu Tinti jump
Patch's way.
Speaker 5: Signal was first detected at three am this morning, and
following confirmation from other radio telescope sites around the globe,
the Pentagon allows that the extraterrestrial radio signal should be
considered valid.
Speaker 6: There are four hundred billion stars in our Milky Way
galaxy and billions of other galaxies as well. It would
be bizarre if we were the only life.
Speaker 7: We're discovering that life forms exist in places and conditions
that we couldn't have conceived of a few years ago.
Speaker 8: Since a good proportion of stars seemed to have planets,
we might expect primitive life to be lighte thread.
Speaker 2: Scientist Robbert Plomer began to verify the exact origin of
the signal.
Speaker 9: What if we get a signal? What will happen? Will
you still go to work tomorrow or will the world stop?
It's the oldest unanswered question that our species has posed
to itself. Is anybody else out there?
Speaker 1: It's a question that Jill Tata has been trying to
answer for over twenty years at the SETI Institute, an
agency dedicated to the search for extraterrestrial intelligence all over
the world. SETI researchers are more optimistic about picking up
that first call from ET than ever before.
Speaker 9: What's so terrific about now is the fact that we
suddenly have the technology that allows scientists and engineers to
try and answer this old question. For me, I can't
imagine doing anything more important.
Speaker 1: Set amongst the dense rainforests of Puerto Rico is the
largest electronic ear on Earth. It's so sensitive it could
pick up a mobile phone on Jupiter. The Araciba radio
dish is one thousand feet across. Twice a year, the
SETI researchers come to Arisibo to listen out for signals
from deep space. Five thousand miles away across the Atlantic
is the love All Dish at Jodrell Bank. This is
the largest radio telescope in Britain.
Speaker 7: The equipment we're using for this search is the most
sophisticated that's ever been used. It's using two of the
world's largest radio telescopes to make the most sensitive system
that mankind has ever been able to use, or probably
will be able to do for ten or twenty years.
Speaker 10: In the future.
Speaker 1: Together, these two dishes are targeting those distant stars most
likely to be orbited by planets. They are trying to
detect alien interstellar messages. But where on the radio dial
will the extraterrestrials be broadcasting? The SETI Institute is currently
scanning twenty eight million radio frequencies.
Speaker 11: Talking about eavesdropping on aliens makes for easy dinner table conversation.
In fact, doing it is quite hard. If you have
twenty eight million channels. He can't just have twenty eight
million guys with earphones awaiting the signal. You have to
have very specialized computers that can look through all those
channels at least once a second and make decisions about
is there something interesting in there.
Speaker 1: Their computers isolate any unusual signals from the constant background
radio noise that swamps the Earth from corner of space.
They're listening out for a special signal, one that suggests
it's been sent by intelligent life.
Speaker 11: You can imagine tuning the radio dial there and you
hear this sh across it due to natural noise sources.
Not very interesting, but every now and again, you could
imagine coming across a squealedol. That squeal it's called a
narrow band signal. That's exactly what we're looking for. Because
only a transmitter, something that's been fabricated, can make a
signal that's narrow band.
Speaker 1: The researchers have to make sure the signal really is
coming from deep space. They must eliminate any transmissions from
passing aircraft, satellite, or military radar. It's only by using
two dishes so far apart that they can calculate if
the signal originates from beyond our solar system. This method
has already picked out one distant signal, though this isn't
from et, it's from one of our own interstellar spacecraft.
In nineteen seventy two, Pioneer ten was launched on an
epic journey to the giant planet Jupiter. It's mission long
since over. Pioneer is now billions of miles beyond our
Solar system, but its signal is still loud and clear.
Speaker 9: Pioneer ten serves as a test case for us. In fact,
it's so far away that its signal looks like a
signal coming from a distant stares.
Speaker 1: Every day the American and the British teams tune into
the Pioneer signal. It's the most distant message they've ever received,
but the scientist's hope for something far better.
Speaker 11: Have we ever found a signal from space that was
clearly due to extraterrestrial broadcasters? Well the answer is no.
I mean, I wouldn't be sitting here if the answer
weren't no. I'd be relaxing on the coach desserve having
a drink. I'm sure we haven't found them yet. So far,
the aliens have been coy.
Speaker 1: Jill Tata and Seth Shostak have both dedicated their lives
to listening out for a message they may never receive.
Speaker 9: Every day when we go to the telescope, we have
some sense of anticipation that we may in fact find
the signal. We put champagne on ice in the refrigerator
here and wherever we observe because we do plan for success.
Speaker 1: The cosmic odds are stacked in their favor and improving
with every new astronomical discovery. There's no shortage of places
a message might come from our own galaxy. The Milky
Way contains over a one hundred billion stars. If every
one of those stars were a grain of salt, they
would fill an Olympic sized swimming pool. How many of
these stars have planets that could be home to an
alien intelligence? Until recently, we could only guess. But over
the last five years astronomers have made an extraordinary breakthrough.
They've discovered over twenty planets outside our solar system, and
they believe there may be literally billions more.
Speaker 12: My guest would be that something like fifty percent of
all the stars in our Milky Way galaxy, which itself
contains one hundred billion stars, probably something like fifty percent
of them harbor planets.
Speaker 1: Jeff Massi is one of the world's most successful planet hunters.
He and his colleagues have discovered more planets orbiting around
other stars than orbit within our own Solar System. Standing
high on the summit of an extinct Hawaiian volcano, the
Giant Telescope is Mars's most penetrating eye on the universe.
In nineteen ninety nine, his team made their most startling discovery.
This time they found not just a single planet, but
three worlds orbiting the same star, Upsilon Andromedy.
Speaker 12: We have found now a complete system of planets, just
like the system of planets we have around the Sun.
These are not isolated freak planets that we had been finding,
but at least in this one case, we now realize
there's a complete system that is very reminiscent of the
ordering of the planets around our Sun.
Speaker 1: This new planetary system lies three hundred and twenty million
million miles from Earth. The closest planet whirls round its
star in just four days, the outermost in four years,
so far, their equipment can only pick out the real heavyweights,
planets the size of Jupiter, but the planet hunters are
convinced there's greater treasure to be found.
Speaker 12: There's almost no question that among the one hundred billion
stars in our Milky Way galaxy there are not just
the large planets that we've been finding, but of course
smaller ones, probably indeed in greater numbers, and so earthlike
planets are out there.
Speaker 1: NASA's proposed Kepler mission may provide the definitive proof of
Earth like planets in the early part of the twenty
first century. This space telescope will continuously monitor one hundred
and sixty thousand stars. Kepler's eagle eye will watch for
any star that blinks, even when a planet as small
as Earth passes in front of it. But if we
do find an Earth like planet, there's no guarantee it
will be home to intelligent aliens. It may be too hot,
too cold, or to poisonous for et to survive, or
perhaps alien life may have evolved on planets where the
conditions would be far too inhospitable for humans.
Speaker 3: One Hi tb hi oh bye bye hiy hight on
bye on tcontob.
Speaker 1: Kan to find out just how extreme an environment can
be and still sustain life. NASA is researching the most
hostile places on Earth before we set out to look
for life on other planets. This research will direct us
where to look. NASA scientist Tony Phillips is searching for
primitive life in one of the coldest places in North America,
high in the Eastern Sierras.
Speaker 3: Right now, we're at the White Mountain Summit. We're at
an altitude of over fourteen thousand feet. The pressure here
is very low during the wintertime. The temperature here is
comparable to the temperature at the South Pole during the
South Pole ar summer, so the environment is very extreme.
Not much lives here, but we suspect that there may
be micro organisms living in the soil or living in
the permafrost beneath the layer of rock, and no one
knows whether they do or not. But that's what we're
trying to find out. Hike Tevi Hike.
Speaker 1: The NAZA scientists. I've discovered that life can survive in
places where no one had expected. It now turns out
that life can survive just about anywhere that there is water.
It doesn't seem to matter how hostile. The environment is
at Yellowstone Hot Springs in Wyoming. Dave D. Murray has
proved that microbial life can even survive in boiling water,
an extreme environment that we never thought possible before.
Speaker 13: The limits for life are much broader than we had
previously suspected. We've now discovered that life can exist up
to one hundred and thirteen degrees centigrade, a higher temperature
than we had dreamed about twenty years ago. But we
find that that is actually a very nice place for
certain organisms to live.
Speaker 1: If life can survive at these temperatures, perhaps it can
live anywhere. Mono Lake in California is one of the
most hostile environments on Earth. Its scenic beauty is deceptive.
The lake is so loaded with salt that it's poisonous
to us. Jack Farmer has discovered that even here life
can find a way.
Speaker 14: In Mono Lake, the salinity of the water here is
two and a half to three times seawater. In addition,
the pH of the water here is around ten and
a half, very alkalin, and yet that's not a barrier
to life. Organisms are thriving here.
Speaker 1: The lake is teeming with microbial life.
Speaker 14: In the last decade, or so, we've begun to realize
that it's really a microbial world. This world that we
live in is dominated by microorganisms. To realize that that
microbial life can occupy a whole range of environments that
we never thought possible before.
Speaker 1: The tenacity of life here in Earth's most extreme environments
encourages many biologists to believe that life may be remarkably
widespread throughout the universe.
Speaker 14: I think the chances of finding life elsewhere in our
Solar system are pretty good. Sometimes I say, well, maybe
fifty to fifty, But I have to be honest, I
don't really know how to put a probability on it,
but I think anywhere where we had liquid water and
the right organic compounds present, we've certainly had more than
enough time to originate biological systems. The probability is probably
pretty good.
Speaker 1: For most of Earth's history, the only living things were microbes.
As they search the universe, scientists expect to find planets
crawling with microbial life long before they find one with
intelligent life. Instead of meeting little green men, they're much
more likely to meet little green slime. Our quest to
discover life on other worlds began optimistically in the nineteen sixties,
when a flotilla of spacecraft headed for our neighboring planet Mars,
but their cameras revealed only craters and extinct volcanoes. Mars
seemed a barren and lifeless world. This gloomy assessment was
reinforced in nineteen seventy six when two Viking craft landed
on the rocky Martian surface. They scooped up soil samples
and analyzed them for any signs of microbial life. The
results were negative. Mars seems extremely hostile to life. The
average temperature is minus fifty three degrees celsius, and the
thin atmosphere provides no barrier to the Sun's deadly ultraviolet rays.
Even the rocks contain chemicals that can destroy living cells.
But the idea of finding life on Mars continues to
obsess many scientists. When Bruce Jaikowski started his research career,
Viking had just landed.
Speaker 3: Viking.
Speaker 15: When it looked for life, it found none, and there
was a real sense that there must be only one
planet in our solar system that could support life, and
that was the Earth. Things have changed dramatically since then,
in particular the Revolution's in terrestrial biology and the possibility
that life could have originated in some of these extreme environments.
Speaker 1: Close up pictures of the Red planet have revealed tantalizing
evidence that water once flowed across the surface of Mars.
Speaker 15: We see clear geological evidence that there's been water on Mars.
On some of the older surfaces. We see networks of
valleys that look like river tributary systems where waters flowed
through them and carved these long channels. The availability of
water at the surface or in the crust, really, I think,
is what makes it possible for life.
Speaker 3: To be there.
Speaker 1: The evidence came sooner than expected. On August seventh, nineteen
ninety six, NASA called an unprecedented news conference. These scientists
had examined a meteorite that had come from Mars and
discovered something very strange lurking inside. One of the microbiologists
on the team was Dave McKay.
Speaker 4: We have a number of forms which it is very
tempting for us to interpret as Martian microfossils.
Speaker 1: The NASA team had been alerted by chemical residues in
the rock that here on Earth can only be made
by microbes. Then they picked out strange wormlike structures that
looked like tiny fossilized life forms. It all began with
a unique discovery on the snowy wastes of Antarctica. Each
year a meteorite survey teams. Meteorites fall all over the Earth,
but here the small, dark rocks are easy to spot
on the pure white ice. In nineteen eighty four, the
team picked up one meteorite ALH eighty four zero zero
one that was to completely change our view of life
in the Uni. It wasn't until nine years later that
researchers discovered that the survey team had brought back a
lump of mass, a rock formed four point five billion
year years ago. Its origin was proved by traces of
gas which exactly matched the composition of the Martian atmosphere
measured by the Viking Landers.
Speaker 16: This is an incredibly complex rock. It's much more complex
than we first realized. It's more complex than most Earth
rocks that people study, and this rock has been studied
more than any rock in the history of the world.
Speaker 1: Some scientists believe the microscopic structures are natural crystals, but
for Mackay, the case for Martian life grows ever stronger.
Speaker 4: These are fossils of little, tiny bacteria single cell organisms.
They're not bones, They're little tiny cells that have turned
to minerals. They're fossilized, but they look exactly like fossils
from Earth rocks.
Speaker 1: But the only way to find out for certain if
there's ever been life on Mars is to go there
and collect a sample. NAS emissions in two thousand three
and two thousand and five will collect rocks from the
red planet and then return them to Earth, where they'll
be dissected for fossils. The surface of Mars is the
same area as all the continents of Earth combined. There's
an enormous choice of possible sights when it comes to
collecting the priceless samples. Mojave Desert in California is one
of the most inhospitable places on Earth. This dry lake
bed was once covered in water. Its parched surface is
the perfect place for Chris mackay to research where NASA
should collect its first samples in order to look for
fossils of microbes that once lived on Mars.
Speaker 17: This lake bed is the sort of place we'd be
looking for on Mars. Is a place to search for
evidence of past life. It's a nice, big, easy to
find target, easy to land in, easy to drive around on,
easy to drill in. If there had been water and
a lake like this on Mars, anything living in it
as a dyed would settle to the bottom, and we'd
be able to find it in the sediments. Here in
the Mohave Desert, we might dig under the surface and
find evidence of life. It's just a few years old,
But on Mars these sediments would be three and a
half to four billion years old, and we'd be looking
for evidence of life that was on that planet when
it was more like the Earth, when it had water.
Here in this desert we find growing just underneath the
surface of certain rocks, microorganisms algae. These organisms grow under
the rocks because the rocks trap a little bit of
moisture so it's not quite as dry. But they have
to grow under the white stones because enough light can
get through the white stones so they can photosynthesize.
Speaker 1: This precarious existence could have been the way that life
on Mars survived for billions of years.
Speaker 17: Who would have been the last organism to live on Mars?
Maybe an organism living underneath the rock. Maybe when we
go to Mars we'll search for relics, for fossils, of
this type of life.
Speaker 1: But perhaps the search will turn up much more than
just fossils. Despite the barren landscape, some biologists are now
uttering what it was for many years a heresy that
microbes may still be living on Mars. Today, microbiologist Todd
Stephens has discovered the deep underground in Washington State, life
is flourishing in apparently solid rock. Until the mid nineteen eighties,
most people thought that the deepest you could dig down
into the ground and find living organisms was around thirty feet,
but Stephens is discovered that life on Earth can thrive
as deep as two miles down. The Columbia River area
of Washington State is covered in ancient lava flows thousands
of feet thick. At the edge of a river gorge
where the lava flows are exposed, Stephens has discovered how
tiny micro organisms can live in solid rock.
Speaker 18: Here at the bottom of the canyon, we can kind
of get an idea of what their habitat looks like.
Here we have the intersection between two basalt flows, and
at one time water has flowed through this layer over
tens of thousands of years and microorganisms live here.
Speaker 8: Well.
Speaker 18: This is exciting because if this is correct, this is
a way that living organisms can live in places where
the surface of the planet is not habitable.
Speaker 1: On Mars, any microbes living deep in the rock would
be well protected from the hostile surface environment. Stephens was
researching the safe disposal of nuclear waste when he made
his startling discovery about life deep underground.
Speaker 10: This one has to be several hundred meter steep in the.
Speaker 1: He took water samples here from boreholes that were drilled
two miles down through the volcanic rock.
Speaker 18: When we sampled the water that was coming out of
the deep aquifers in this volcanic rock, we were kind
of surprised to find that each leader of water contained
between a million and one hundred million microbial cells. And
we know that the vast majority are actually attached to
the rock, so there's many more than that down there.
Speaker 1: To prove they could survive without sunlight, Stephens bred the
microbes in his laboratory, simulating their subterranean world. His results
confirmed life's amazing ability to live anywhere there's water. These
bacteria stained red feed off hydrogen gas created when water
reacts with the volcanic rock. Even more exciting, these bacteria
bears striking resemblance to the apparent fossils found in the
Mars meat. You're right, perhaps the descendants of these fossilized
microbes are still living deep under the Martian surface. The
temperature on Mars is well below freezing, any life near
the surface would be frozen solid. Astrophysicist Richard Hoover has
made the astonishing discovery that microbial life can be re
animated even after it's been frozen for thousands of years.
The Fox Tunnel in Alaska is one of the coldest
places on Earth. It was originally excavated for gold mining
and dug out of the permafrost, where even the soil
one hundred and fifty feet below the surface is frozen solid.
Speaker 10: We have found microorganisms in the permafrost of Earth that
are alive, and yet they have been frozen for up
to three million years. Therefore, it is possible that there
may be microorganisms frozen in the permafrost of Mars.
Speaker 1: By warming samples from the permafrost, Hoover can revive these
dormant organisms. It's not just microbes that wake up when
the temperature rises. Even plants like moss can be brought
back to life.
Speaker 10: I have here a moss that was frozen in the
permafrost for forty thousand years, and after it was extracted
from the permafrost, the moss started to grow. It realized
that the weather had gotten better and it was time
to grow again.
Speaker 1: As they're warmed up, any samples of life collected from
Mars by NASA may also be revived. Returning a piece
of Mars to Earth will require the strictest quarantine. It
may be the most risky venture the human race has
ever undertaken. No one knows what might happen if Martian
bugs were released onto our planet.
Speaker 4: If there's life on Mars, we have to be cautious
because that life is not understood, and as we know,
microbial life can be quite dangerous. Both viruses and bacteria
could be dangerous to humans. It can also hurt the environment.
Speaker 1: Unlike the meteorites, which have been sterilized by natural radiation
as they travel through space, these rocks will have been
transported directly from Mars.
Speaker 4: They will be treated as if they might have an
incredibly dangerous microbe in them. We don't know that, we
don't think that'll be true, but we can't afford to
take the chance.
Speaker 15: Three two whe Bishop.
Speaker 8: And with good of Atlanta Law.
Speaker 1: In nineteen eighty nine, space shuttle Atlantis set off on
a mission that may lead us to the first definitive
discovery of life beyond our own planet. On board was
the unmanned Galileo spacecraft, bound for the king of the
planet's Jupiter. In this remote, frozen region five hundred million
miles from the Sun. The last thing the mission scientists
were expecting to find was signs of life. Giant Jupiter
is big enough to swallow the Earth a thousand times over.
Its family of moons forms a miniature solar system. The
four biggest are io Ganymede, Callisto, and Europia Brilliant white.
Europa is completely covered in ice. It surface crisscrossed by
strange grooves. Many scientists now believe that this frozen world
is the most likely place in our solar system to
be harboring extraterrestrial life. The nearest equivalent to the surface
of Europa are the glaciers of the Arctic.
Speaker 10: The microorganisms that are found in the glaciers and in
the polar ice caps give us a good model for
the types of microorganisms that might be found someday when
we bring back samples from Europa. I have become very
excited when I look at the beautiful pictures of Galileo
of the surface of Europa because we see magnificent colors,
and those colors are very similar to colors that we
see in bacteria and algae on Earth due to the
pigments of these microorganisms. When we do get samples back,
we will have a good idea of what types of
things to look for, and we will have the ability
to recognize the microorganisms when we find them.
Speaker 1: The microbes of Europa would have to be far tougher
than their Arctic counterparts. They'd have to survive lethal doses
of radiation generated by Jupiter's powerful magnetism.
Speaker 10: We know that there are microorganisms on Earth that have
evolved to have the ability to withstand intense levels of radiation.
There are bacteria that grow on the cooling of nuclear reactors,
and if in fact organisms live on Europa, then they
would have had the ability to adapt to these high
radiation levels. So we must always be cautious about saying
that life cannot do things, because quite frequently we find
that life does exactly what we think it's not capable
of doing.
Speaker 1: The cracked ice surface may suggest something even more exciting.
Heat from the core of the Moon may have melted
the ice from below, just like the cracked octag iceed
sheet on Earth, Europa's ICE's surface may overlie a huge
ocean of water.
Speaker 19: All life as we know it utterly depends on liquid water.
Europa may be the only other place in the Solar
System where there's an ocean of water, and that means
it's the most exciting place to go and look for
life Elsewhere.
Speaker 1: Beneath the icy crust of Europa could lie an ocean
as deep as sixty miles. This cold, dark environment seems
a fruitless place to look for living organisms, but the
depths of the Earth's oceans prove that life can once
again flourish in the most unexpected places. In the nineteen seventies,
the lights and cameras of deep diving submersibles discovered vents
erupting hot water from the ocean floor where no sunlight
ever penetrates and the surrounding water verges on. These volcanic
vents support the most exotic life forms on Earth.
Speaker 19: It's certainly possible that those sorts of hydrothermal events exist
on Europa. There may well be teeming communities of organisms
at hydrothermal vents at the very bottom of Europa's oceans.
Now on Europa, that's one hundred kilometers down. The oceans
on Europe are much deeper than they are on Earth,
so those are not going to be easy to reach
and investigate.
Speaker 1: Around twenty ten, NASA plans to send its most ambitious
unmanned mission ever, touching down where scientists suspect the ICE's thinnest.
The Europa Lander will lower a probe that melts down
through several miles of ice. A second probe, a hydrobot,
will swim down to the bottom of the ocean. As
it descends, it will transmit live pictures back to Earth.
The hydrobot will be programmed to seek out hydrothermal vents,
the most likely place to find life. This will be
the most alien environment we have ever explored. Will it
be teeming with tiny microbes or perhaps oh to fully
developed alien creatures. Even if we do discover life in
our Solar system, scientists believe that it will be fairly primitive.
If we want to find complex life forms like us,
we'll have to look far beyond our neighboring planets.
Speaker 15: If we want to think about intelligent life, we need
to look past our solar system. We need to look
at the possibility of earthlike planets orbiting other stars and
whether life might have originated there, And then we need
to think about communicating with them.
Speaker 1: Any nearby aliens would already know that we are here.
For the last seventy five years, Earth has been leaking
radio and television transmissions out into space.
Speaker 15: Dragging the sound.
Speaker 1: Our broadcasts reached the nearest stars four years after they
are transmitted on Earth.
Speaker 10: Pounds of Nazi, one.
Speaker 8: Of the circumstances that were.
Speaker 1: Our oldest signals, broadcast in the nineteen twenties, have traveled
past one hundred thousand stars in our galaxy.
Speaker 7: Of the entire.
Speaker 1: World beyond this point, seventy five light years from Earth,
no one would have any idea of our existence. Alien
civilizations may be far older than the human race. Dan
Wortheimer is pioneering a completely new approach to intercepting their
interstellar messages.
Speaker 6: We don't really know what other civilizations are going to
be doing, so we ought to try a lot of
different strategies and not put all our eggs in one basket.
Perhaps other civilizations, instead of sending US radio waves, are
sending us light waves, perhaps from very bright lasers.
Speaker 1: Wortheimer is hoping to intercept laser light messages that extraterrestrials
are beaming across the universe. On Earth, we can produce
laser light signals a million times brighter than our sun.
We have already transmitted our own laser beams to the
Moon and back. If we can do it, worth Timer
believes that et can do it even better. Here at
the Loisner Observatory in California, his telescope is linked to
a high speed computer that's searching for a spike of
a pure color of light, the telltale signature of a laser.
Over the next few years, this telescope will scan two thousand,
five hundred stars.
Speaker 6: We're looking for a very bright pulse. It would only
be on for perhaps a billionth of a second. It's
like looking for the kind of flash that you'd see
from a lighthouse. As the beam comes around, you'd see
a sharp pulse, very bright, and then it would go
off for a while, but then you might see it again.
Speaker 1: Hidden in these short pulses could be a whole encyclopedia
of information, coded like our own computers.
Speaker 6: If they send us a signal intentionally, it's likely that
they will make it easy for us to understand that message.
It will have language lessons.
Speaker 10: Lots of pictures, vocabulary.
Speaker 6: Lessons, and then they would send us a huge amount
of information, all their music, their poetry, their literature, their science,
their medicine. That would be an amazing feet.
Speaker 1: It's an opinion that may be naive. The aliens could
turn out to be worse than any science fiction nightmare.
Speaker 8: I think it would be a disaster. The extra terrestrials
would probably be far an advance of US.
Speaker 1: Astrophysicist Stephen Hawking believes that not all aliens will be friendly.
We should take heed of past experiences on Earth.
Speaker 8: The history of advanced tress is meeting more primitive people
on this Lanet's not very happy when they were of
the same species. I think we should keep our heads slow.
Speaker 6: I don't think that other civilizations are going to come
and eat us. There are not that many raw materials
on Earth. There are much bigger planets. And also I
suspect that advanced civilizations are not killing each other the
way we are.
Speaker 1: But even if they are aggressive. The sheer size of
the universe makes it unlikely that we will meet an
extraterrestrial in person. Imagine yourself as one of the crew
this Faster than Light spaceship of the future. Hollywood and
science fiction try to convince us that it's easy to
travel to the stars faster than the speed of light.
So far, the fastest we can manage in our current
spacecraft is forty thousand miles per hour. At this rate,
it would take seventy thousand years to reach even the
nearest stars. The only realistic way to make contact is
to eavesdrop on alien signals, and we may be communicating
with aliens sooner than we think.
Speaker 6: I'm optimistic. In the long run, probably in our lifetimes,
maybe fifty or one hundred years, we will be in
contact with other civilizations.
Speaker 7: If we did find signal, it's bound to have a
fantastic effect on our human civilization. I don't think it
be any worry or any panic, but we would know
for the first time that other life exists.
Speaker 9: We may find out that we are just one of
many civilizations in the universe. Well, we may find out
in the end that we are extremely unique. So maybe
we're alone, maybe we're not. Either way, the answer is
really significant at evening w