For over half a century,
we've searched for radio signals
from extraterrestrial civilizations.
But it's, been, well, a little quiet.
Are they ignoring us?
Or have aliens already made contact
without us knowing it?
The truth could be hiding in plain sight.
This is WHAT IF, and here's what would happen
Since the 1960s,
scientists at SETI
(the Search For Extraterrestrial Intelligence)
have had their ears to the skies,
listening for signals
that could prove the existence
of exterrestrial life.
Recently, bizarre and intermittent fast radio bursts
were detected coming from a spiral galaxy
like the Milky Way,
500 million light-years from Earth.
Some scientists wonder
if these pulsating signatures from space
are the result of mini black holes,
or pulsars,
or even alien megastuctures.
But could these signals
actually be aliens
trying to communicate with us?
Scientists at Harvard theorized
that the energy needed to send a radio signal
to a distant galaxy
would require a planet twice the size of Earth
covered in energy collectors.
While it is possible,
scientists have found an easier way
for aliens to talk to us.
And according to Robert Zubrin,
it could involve teeny-tiny interstellar light sails.
This idea has been gaining enough ground
that the Breakthrough Starshot project
is working on nano-spacecraft.
Someday, they hope to beam them
all the way to Alpha Centauri.
While tiny spacecraft could travel great distances,
bacteria could potentially survive the journey as well.
This is because it's easy for a bacterium to duplicate itself.
And as microorganisms,
they are small enough to overcome the gravity of stars,
making it possible for them
to travel interstellar distances.
Hypothetically, a microbrial nanocraft
could be beamed from Earth
and travel a distance
of one light year every 10,000 years.
In 50,000 years, it could reach nearby stars.
But why would aliens be sending us bacteria?
Well, the answer is in DNA.
Just one gram (0.03 oz) of bacteria
could be encoded with about
900 terabytes of DNA data.
Imagine a 200-page book.
Now imagine 2 billion of those books.
That's how much data.
In fact, microbiologists think that
alien messages may already exist,
hidden in DNA here on Earth,
waiting to be decoded.
Researchers suggest these messages
could be found by
determining which bacteria
could survive the conditions of space.
In fact, some astrobiologists
on the ISS (International Space Station)
have experimented to see if all life on Earth
could have come from extraterrestrial microbes.
This theory, known as
suggests that microbes may have hitched a ride
on a comet that crashed into Earth
So, maybe we're the aliens.
"woah"
Okay, okay, but are we really alone?
While microbial alien messages could exist,
we're still not sure
what these alien messengers might look like.
We're mostly familiar with terrestrial life,
where all living beings are made from cells
using molecular machinery.
With most life here on Earth
being carbon-based,
we might just be looking
for the wrong kind of life.
Many biochemists suggest that
silicon-based lifeforms could exist.
In fact, some scientists,
including British chemist and astronaut Helen Sharman,
suggest that aliens could exist in a place
we cannot see or study,
known as a shadow biosphere.
These invisible aliens could exist
at a microscopic level
beyond our comprehension.
With recent UFO sightings
being declassified by the Pentagon,
many people believe
that aliens have already visited us.
Maybe, in the not too distant future,
with the help of SETI,
we'll finally prove that
we're not alone.
For more on this,
tune in to our What If Discussed podcast.
This week, we talk to Dr. Andrew Siemion,
astrophysicist and Director of the Berkeley SETI Research Center.
He'll join us for a deeper dive into the subject
and update us on SETI's progress
in its comprehensive search
for alien communications.