from bizarre sightings to government
cover-ups people love a good story about
aliens we've always been a bit obsessed
with them just think about all the films
they star in at
found home
our home earth
is filled with life so far unmatched by
anything we've found in space but we're
only a tiny part of the universe
there has to be life out there somewhere
else right
scientists have been trying to answer
that question for decades
but today research is skyrocketing
the next decade is probably going to be
packed with the most insights and the
most data and the most knowledge in all
of human history could we really be
about to discover whether life exists
out in space
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ancient greek philosophers theorized
about it
18th century academics like voltaire
wrote about it but the scientific search
for life beyond earth really kicked off
in the 1950s with the dawn of the space
age
by october 1957 the first artificial
earth satellite was pronounced ready
when the russians sent the world's first
satellite into space the race was on
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by the 70s everyone wanted to know the
answer to one question
by 1976 america had landed a probe on
our neighbor planet
the world held its breath to see what or
who might be up there
who who are you we're from mars don't be
afraid but the reality was a bit
disappointing sorry bowie as soon as
people sent satellites into orbit and
beyond they immediately discovered that
these places didn't actually have life
the search for life was very prevalent
in science fiction but in science it was
seen as a little bit of a laughing stock
there's no way of actually doing it we
didn't have enough technology to do it
but in the last two or three decades
astrobiology as a discipline has become
this incredibly exciting frontier
not only for these big questions that
many of us are interested in because of
popular culture because scientifically
we can start to answer them properly
but in the search for life beyond our
own planet what are we actually looking
for
scientists hope to detect three things
that can signify life
the first is water
water is the solvent for life on earth
it means that life works so water is the
first thing that everyone has been
looking for
for liquid water to exist on a planet's
surface it has to be a very specific
distance from the star it's orbiting
not too far away
so that all the water on its surface
will freeze but the planet is also not
too close to the sun
so that it's not so hot all the liquid
water on the surface would become vapor
this perfect distance is nicknamed the
goldilocks zone
not too hot not too cold
in the past 10 years scientists have
found 59 worlds outside our solar system
that are just right
the planet with the most potential is
called tea garden b
12 light years away it is roughly the
same size as earth and receives a
similar amount of light from its host
star
but it's one thing to think a planet
might be able to sustain life it's
another thing entirely to know it
actually has it
what you then need is individual
biosignatures
and biosignatures is a very loose term
but what it basically means is
specific molecules are only associated
with life elements like oxygen which
life on earth produces and replenishes
or methane a compound life on earth
creates
astrobiologist sarah seeger has
identified at least 3 500 molecules that
could be biosignatures
so there are plenty to look for
but finding biosignatures does not
necessarily mean intelligent light
for decades scientists have also been
looking for something called techno
signatures
if life evolves on the planet and gets
to the point where it's it can
communicate and build things and build
technology
like humans
then you can detect signs of that too
techno signatures aren't that tricky to
pick up on
all you have to do is watch for telltale
signs of technology like radio signals
or the bright flash of a laser despite
looking
scientists have failed to find a
convincing techno signature but in 1977
astronomers saw something that stopped
them in their tracks a strange signal
coming from space
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a handwritten note alongside says it all
wow
which became the signal's name
where this apparent signal came from
no one knows
some might claim it is proof of life
beyond earth but it hasn't been verified
and finding genuine signs of alien
technology relies on getting extremely
lucky with timing when you're looking at
a planet that's maybe 200 light years
away let's say so that means you're
seeing that planet 200 years ago
and vice versa that planet if life
exists and it's technological it's
looking at us and it looked at let's say
london
they'd see victorians walking on the
streets right now
because that's that's how i'm going to
take taken for the light to get there
now bear in mind also that these
civilizations might be hundreds millions
of light years away so the communication
is not exactly quick
and we're talking many hundreds of
generations of people on earth before
you get responses so detecting alien
intelligence is really tantalizing but
it's also tragic because we'll probably
never be able to communicate with them
if we did discover it
that's why today's technology focuses
more on looking for the bio than the
techno
so how are we looking for biological
life
one way is to scour the skies
that means telescopes
but not like those
more like these
so for several decades now there have
been telescopes in space and on earth
that have been able to detect the
presence of planets around other stars
now the next generation of telescopes
will be able to take pictures of those
planets
in much more detail
in december 2021 the largest and most
powerful space telescope ever made was
launched into orbit
the james webb space
telescope james webb begins a voyage
back to the birth of the universe
it's equipped with a 6.5 meter mirror
giving it a light collecting area more
than six times greater than the
world-renowned hubble telescope if we
crave some cosmic purpose
then let us find ourselves
a worthy goal it's also able to detect
molecules of life like oxygen a handy
tool when looking for a habitable
environment
towards the end of the decade there are
going to be enormous ground-based
telescopes with 40 meter wide lenses and
these will be able to actually take
pictures of things like clouds and
atmospheres on these exoplanets so
you'll be able to do things like
understand the climate of a different
planet you'll be able to understand what
a day looks like on all these planets
which is incredible
in the 2020s three ground-based
telescopes with mirrors 25 to 40 meters
wide are expected to become operational
in the late 2030s they could be joined
by two proposed nasa spacecraft
one being specifically designed to take
photographs of habitable planets
an even better way of looking for signs
of life is to visit places to scoop up
bits of air or soil do scientific
experiments with them using
sophisticated instruments to really
understand what's there and there are
many many missions planned for the next
decade
probes are being sent to collect data
from so far untouched parts of our solar
system
like europa one of jupiter's moons which
seems to have canyons of ice
ice means that precious life-giving
elements water
in 2023 europe's jupiter icy moon
explorer will embark on a 12-year
journey to see if it has the potential
to support life
life on earth started
with
warm water sitting on rocks and
interacting chemically then perhaps it
could happen on one of those sorts of
moons too when it comes to general space
exploration these are quite cool
missions anyway but they're all pretty
much geared towards looking for life in
ways that we've never been able to do
before
these missions cost hundreds of millions
of dollars luckily there seems to be a
growing appetite to answer the
fundamental question of whether life
exists beyond earth
nasa's 2022 budget is the largest it's
been since the 60s
astrobiology has really come of age the
2020s is when it's going to take flight
if life exists within our corner of the
galaxy most scientists in this field are
confident that we'll discover some sign
of it in the next decade if however we
discover nothing in the next decade that
also tells us something profound it
tells us that life is much much much
more rare than we thought it was
i'm alek science correspondent at the
economist to read more on this topic
please click on the link opposite thanks
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