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CLARA SOUSA-SILVA: Finding signs of life on other planets
beyond the Earth would be a way of answering the biggest
questions that we've had as a species so far.
Where do we come from?
Are we alone?
Of course these questions are not the exclusive purview
of scientists.
People have been asking them for as long as
is any record of them being able to ask these questions.
What is special about this moment and our role in it
as scientist, is that for the first time
we're actually able, because we have the tools to answer
these questions.
JANUSZ PETKOWSKI: So a group of scientists, led by Jane Greaves
from the University of Cardiff, were looking for signs,
for chemical signs on Venus, that shouldn't belong there.
And one of such molecules is phosphine.
And they, unexpectedly, they actually
were able to find a signal that belongs to this molecule.
So then, we raced to figure out what
could be the reason for phosphine on Venus.
And this is where our MIT team comes.
When we actually looked at all kinds of processes, chemical
and physical, that could potentially produce phosphine
in Venusian environments.
This is a atmosphere.
The surface of the planet is completely, completely uninhabited.
The atmosphere is the only place in which life actually
could in principle exist.
There is a belt of clouds.
And we concluded that there is no known chemical and physical
process that could conceivably produce phosphine.
So this adds to the mystery of Venus.
And then, this opens a rather bold possibility
that there might be something living in the clouds of Venus.
CLARA SOUSA-SILVA: Phosphine is my favorite molecule.
And it looks more or less like this,
a phosphorous atom on top, and three hydrogens
in the base of this pyramid.
And phosphine is an extremely difficult molecule to make.
It is only spontaneously made in extreme environments.
Such as what you find in the hellish depths of Jupiter
and Saturn.
It is otherwise only made either naturally by life on Earth
or artificially by humans, as a fumigant for example.
JANUSZ PETKOWSKI: So the question
is why it is actually a staggering discovery.
Why it is so important?
Well, there are a couple of angles that you can actually
answer that question.
One, the first, is that phosphine
is absolutely unexpected.
It cannot be produced on the rocky planets.
At least we don't know of any known processes, chemical
or physical, that can produce phosphine.
Which means, either our understanding
of the physics and chemistry of the rocky planets
is severely incomplete, or there is
some chemistry, that is so unbelievably weird, that it
could even be life.
CLARA SOUSA-SILVA: If we have indeed found life
outside the Earth, it puts our own existence into perspective.
But it also tells us that life would be much more
common than we first imagined.
And there is a huge array of possibilities
out there in the galaxy of life with different biochemistries
and desire.
And of course, if we have found life
right next door in a planetary neighbor,
that would be so cool.