this is a planetary emergency evacuation
please remain calm and board your space
shuttles you know even though humanity
might not have to leave the earth in
your lifetime
we should start preparing early on not
only could it take centuries to set up
the relocation program it would take
generations to move to a potential new
home that right there is Proxima
Centauri B or just Proxima B it's the
closest potentially habitable planet out
there its temperatures are in the
bearable range and it could have just
the right breathable atmosphere we only
have to get there how long would our
journey last how many people would we
send to populate the new world
successfully and what if it turned out
that Proxima B wasn't as habitable as we
thought this is what if and here's what
would happen if we relocated humanity to
Proxima be
when astronomers started finding planets
outside our solar system or exoplanets
we realized that there are many worlds
out there that meant that Earth doesn't
have to be our home forever and that we
don't have to die with our planet when
the Sun engulfs it some five billion
years from now
[Music]
now that we found over 4100 exoplanets
we've learned something rather
disappointing not all exoplanets are
good for humans to live on most of the
worlds we've encountered are either ice
giants like Neptune or gas giants like
Jupiter and Saturn only 161 of those
planets are terrestrial like Earth and
when it comes to sustaining human life
being terrestrial isn't quite enough
Proxima B is very promising it orbits a
red dwarf star called Proxima Centauri
in a system with three stars in it
Proxima Centauri is small it only has
between seven-and-a-half and 50% of our
sun's mass that's a good thing because
the red dwarf Proxima Centauri is so
much smaller than our yellow dwarf Sun
it burns at a lower temperature it takes
stars like Proxima Centauri much longer
to burn through all of their hydrogen
supply because of that Proxima Centauri
has a lifetime of trillions of years
while our Sun has a ten billion year
expiration term
that alone makes Proxima be a good
candidate for relocation that and the
fact that its orbit lies in Proxima
Centauri's habitable zone that means
there's the potential for liquid water
and comfortable surface temperatures if
we're lucky
Proxima B would have an atmosphere that
we could breathe if it does the surface
temperatures would be in the range of 30
degrees I don't know about you but I'd
move there right now I just need to warn
you then there are a few problems a trip
to Proxima B would be long and very
dangerous Proxima B might be the closest
habitable exoplanet we've got but that
doesn't mean it's close the red dwarf
star Proxima Centauri is about 4.3 light
years away that means that if you could
travel at the speed of light it would
take you four point three years to get
there
nothing we've built so far can reach
that kind of speed
realistically a trip to Proxima Centauri
in a space shuttle would take 165
thousand years give or take that's right
some of the colonists would be born in
transit
some of them would never see the earth
some of them would never see Proxima be
they just live their lives aboard the
spaceship and die in space how many
humans would we need to send on a
mission exactly well according to some
calculations 98 people would be just
enough their descendants would arrive at
Proxima be with enough genetic diversity
to populate the entire planet and that's
accounting for possible cases of
infertility inbreeding and sudden deaths
in those calculations the crew would be
travelling on something faster than a
space shuttle their mission to Proxima B
would only take 60 300 years but don't
be surprised technology is constantly
improving right now a scientific and
technological program called
breakthrough initiatives is looking at
how we can get in the neighborhood of
Proxima Centauri within one generation
their project star shot is working on an
ultra-light unmanned probe that would
reach the star system in just 20 years
now I definitely need to sign up but
again Proxima B is really far away it's
so far that we can't even see if it has
an atmosphere it might just happen that
we would arrive at a frozen planet with
surface temperatures of minus 40 degrees
and even if it has an atmosphere it
might not be the right one we might
still enjoy warm temperatures but we'd
be doing that in spacesuits with oxygen
tanks
or Proxima B could be tidally locked to
Proxima Centauri meaning that one of the
planets sides would always face its star
and the other side would be plunged into
darkness space flight itself could bring
some unpleasant surprises spending an
entire lifetime in a zero-gravity
environment would lead the crew members
to lose muscle and bone density they'd
be constantly exposed to space radiation
their microbiomes immune systems and
physiology would all be different from
ours they wouldn't be the same kind of
humans as we are they would change their
values culture they might forget all the
farming techniques we teach them to
sustain themselves in space and on their
new planet they might change their mind
about the mission altogether and just
turn their spaceship in a different
direction who knows they might even come
back to earth and take revenge for all
those years they were forced to spend in
space if that happens I'll be asking for
a refund sending anyone on a mission
like this is a huge risk we'd need to
design and build a vehicle choose the
space travelers very carefully supply
them with all the food and water and
make sure they could become
self-sustaining we'd have to design new
propulsion navigation hibernation and
life-support systems and we have no way
of knowing if Proxima B is actually
habitable well now I don't really feel
like going there do you maybe a better
idea would be to build a mega structure
somewhere closer to the solar system but
that's a story for another what-if
[Music]
you