All language subtitles for Exploring.Venus.S01E03.WEBRip.x264-ION10_English

(piano music)

- [David] There's one very
tantalizing possibility about

the clouds of Venus, which
is that some of us think that

it's plausible, that there
could be life in the clouds.

- [Sanjay] Something is absorbing sunlight

in the clouds of Venus.

Maybe there's some microorganisms.

Venus has a habitable
zone in the cloud layer.

So life could exist there.

- Four and a half billion years ago,

we had three terrestrial
planets, all with oceans,

life evolved on one.

Everything that we know about
chemistry, about physics,

about geology suggests that
those conditions were there

on Mars and Venus, too.

- The presence of liquid water,

the presence of organic molecules,

the presence of some kind of
energy sources and some sort of

stable enough environment
for interesting chemistry

to happen and take root.

There's every reason to believe

there was an origin of life on Venus.

We don't know if there was,

but if we're correct about
what it required on earth,

there's no reason to think
it didn't happen on Venus.

- We know on earth that once life forms,

however that happens,
life, life is tenacious.

Earth is dripping with life right now.

It's in every crevice. It's
an it's in the atmosphere.

It's in every niche that we have on earth

after 4 billion years,
it's it's everywhere.

So in my mind,

if the environment is driving
the evolution of life,

those environments were certainly there

four and a half million years
ago on those three planets.

- And so it may well have
been that Venus and Earth

and Mars too, for that matter

all three planets seem to
have had those conditions

for an origin of life and
habitability early on.

It may be that,

that our system had multiple
nearby habitable planets.

And if there was going to
be life on Venus, you know,

life as we know it, made out
of carbon molecules and such,

it could not be on the
surface of the planet.

It's just too hot, but there
is an environment in the clouds

where it's at least
plausible there could be some

sort of biota.

So in addition to all
the other reasons we want

to study the atmosphere
and the clouds of Venus,

there's this exotic
possibility that we could even,

who knows, maybe discover life there.

- My Venus atmosphere friends
talk about the fact that

there is a signature in the atmosphere

that they can explain.

And there is something in the clouds

that absorbs UV radiation,

and they don't know what it is.

That signature may be due to

absorption by biota, by cloud creatures.

- Venus is completely covered with clouds.

If you actually look at
Venus through a naked eye,

you don't see any detail at all.

The cloud cover is almost
like a fog bank that's global,

from fritter to pole.

And within this fog of these patches,

you can see these patches
moving very rapidly.

The Venus winds are extremely
fast, but these patches,

they are a mystery.

You know, these patches would have seen

from most telescopes
more than a century ago.

The mystery has remain for all this time

as to what is causing that absorption,

these patches are because
something is absorbing sunlight

in the clouds of Venus.

Bacteria could be the absorber.

We know on Earth that the
clouds harbor bacteria.

- We have life in the clouds of the Earth.

Now that life comes from
the surface of the Earth

and has been transported up.

Lifeforms can exist in the clouds.

And there's certainly enough
energy in the clouds to support

life on Earth. And maybe on Venus.

You need water, you need
something for it to eat.

The temperatures in the clouds of Venus

are shirtsleeve weather. Okay?

So that's not a problem.

- The temperature and pressure conditions

in Venus's atmosphere

are pretty similar to what
we experience here on Earth.

So similar temperatures
may be a little warmer

than we're used to.

The main difference at
that part of the atmosphere

of course, is the carbon
dioxide and the sulfuric acid

that makes up the cloud layer.

But it's possible.

We know of organisms that can thrive

in those types of environments on Earth.

- The one impediment to life,

maybe the strong acid in the clouds,

but we've learned more
recently of all these

extremophile organisms on earth,

including what we call
Acidophilic organisms;

organisms that love living in strong acid.

The more we've learned
about strange life on Earth,

the more we sort of dare
contemplate the possibility of

life in strange environments
on other planets.

- If Venus had habitable
conditions for much of its history,

then it's possible that life
could have evolved to live in

all kinds of ecological niches.

Just like life has on Earth.

Earth has had 4 billion
years for life to fill every

ecological niche possible.

And we find life everywhere
we go, we dig deep wells

we find life down there.
We find life in the clouds.

And then there's another school of thought

that there would be a kind
of a panspermia type of event

where there is mass exchange
between the planets.

There is a really good
chance that rocks from Earth

or even from Mars would
have ended up on Venus.

And if those carried
extraordinarily robust organisms

extremophiles, as we
call them here on Earth,

they could also populate different aspects

of the Venusian atmosphere.

- If we have the
opportunity to go to Venus

and float in the Venus clouds,

we should at least think about

if we can measure the conditions
that might be reasonable

for life today,

and also any signature of life
in the clouds of Venus today.

- If you want to look for life, you know,

right now we have about five objects.

We have a Venus, we have
Mars, Europa, Enceladus,

and Titan.

I think of these five
objects, I would argue that

Venus should be a top priority.

At least in the case of Venus,
the search should be easy.

You can launch today a
space car toward Venus

and be there in about
three to five months.

So the journey is quick,

you don't have to wait for your
children to analyze the data

that you work hard to update.

You don't need to find a
place to land on Venus.

Look for life. On Venus,
go anywhere in the clouds,

in the low latitudes. And if there's life,

you should find it because
it's there everywhere.

If it is there at all.

(pensive music)