Should we be looking for life elsewhere in the universe? - Aomawa Shields

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As the number of “potentially habitable” planets that astronomers find continues to rise, we seem ever closer to answering the question, “Are we alone in the universe?” But should we be looking for life elsewhere? If we were to find life in one of these worlds, should we try to contact any beings who may live there? Is that wise? Aomawa Shields navigates the murky waters of pursuing curiosity.

Lesson by Aomawa Shields, animation by Boniato Studio.

Astronomers have discovered thousands of
planets orbiting stars other than the Sun.

They come in all sizes,

at different orbital distances
from their stars.

The closest of them are trillions
of miles away,

and even the largest
are just fuzzy patches

in the fields of high-powered telescopes.

But if one of these planets is close
in size to the Earth

and orbits not too close
and too far away from its parent star,

it could be rocky and warm enough
to have oceans

and perhaps life.

Astronomers discover these potentially
habitable planets,

and their eyes get big and wide.

Could one of these distant worlds
carry the building blocks of life?

Or even a living, breathing, civilization?

Is the question, "Are we alone
in the universe?" about to be answered?

But wait.

Maybe we should
ask a different question first.

Should we try to find out
if we're alone in the universe?

If we do find the atmospheric
fingerprints of life

on one of these small,
distant worlds,

should we try to contact any beings
who may live there?

Is that wise?

Three decades ago, NASA decided
the answer was yes.

Voyager 1 and 2 were launched in 1977

to explore the giant planets
in the solar system.

Each spacecraft carried a golden
phonograph record,

a time capsule of sorts that included
clues and messages

meant to convey the story
of human civilization.

The contents of these gold-plated
copper disks were chosen by a committee

chaired by American astronomer
and author Carl Sagan.

They included over 100 images,

and a range of sounds
from the natural world:

ocean waves,

thunder,

the sounds of birds

and whales.

The records also included music from
many different time periods and cultures,

greetings in 55 languages,

and messages from
the President of the United States,

and the UN Secretary General.

They also included a map.

Each golden record displays the location
of our solar system

with respect to fourteen pulsars.

Their precise, unique frequencies
were indicated

so that intelligent,
extraterrestrial lifeforms

could use them to find the Earth.

Many years later, renowned physicist
Stephen Hawking said

that it was a mistake to give
an alien species a roadmap to our planet.

Hawking suspected that any
extraterrestrial life

probably wasn't any more complex
than microbes,

but he warned that if an advanced
alien species did visit Earth,

it could be as catastrophic as
Christopher Columbus's arrival was

for the Native Americans.

Meanwhile, the golden records
continue their journeys.

In 1990, both Voyager spacecraft
passed beyond the orbit of Pluto.

Voyager 1 entered interstellar space
in 2012,

and will reach the nearest stellar system
in 40,000 years.

If either spacecraft is discovered
by extraterrestrial life,

there's a possibility that they could
decipher the clues from the golden record

and one day reach our planet.

That's particularly true

if theirs is a much more
technologically advanced civilization.

That life could be benevolent,

as we would hope to be if humans are one
day able to achieve interstellar travel.

Or it could be hostile.

Searching for planets that might have life
means staring into a great abyss.

We'll likely have no clear knowledge
of the evolutionary stage,

sentience,

character,

or intentions of the first form of life
we discover.

So it's a risk to turn our eyes outwards.

We risk our very way of life.

But it may be a greater risk not to look,

to deny the very pioneering spirits
that help shape our own species.

We are all born curious about the world
and the universe.

Pursuing that curiosity is one of
humankind's greatest achievements.

Perhaps there is room to push
the frontiers of science,

provided that we cradle alongside
our fervor

another of humankind's greatest assets:

hope.