- [Narrator] Despite decades of searching
distant planets and stars for alien life,
we're still empty handed.
Turns out, we may have been looking
in all the wrong places.
And the answers could actually be
much closer than we thought.
(mysterious music)
Life could actually be right next door,
floating on the lower clouds of Venus.
Venus has some mysterious dark patches
that might be swarms of alien microorganisms.
Scientists have known about these patches
for nearly a century.
They first gained attention
because they change shape so often.
Morphing from small patches to giant blobs
over a matter of days.
It looks kind of like a lava lamp.
- [Narrator] For decades no one
could come up with a convincing
explanation of what was really going on.
Then, in 1967, famed astronomer Carl Sagan
suggested that the clouds could support alien life.
And now, a team of scientists have new evidence
to back this idea.
- [Narrator] He's referring to algae blooms,
you know, they're those green blobs in lakes and oceans.
And they're teeming with bacteria.
And incidentally, they grow and change shape
just like the patches on Venus.
But of course, scientists need more than shapes to go on.
They need proof that bacteria like this
could theoretically exist in Venus's clouds.
Which, at first glance, doesn't look all that inviting.
They're not made of water or ice like the clouds on earth.
Instead, they contain toxic sulfur dioxide
and sulfuric acid.
But digging a little deeper, scientists found
exactly what they were looking for in India.
It's a special type of bacteria.
This bacteria can withstand highly acidic environments,
and stay aloft in clouds on earth.
It's a big stretch to say that these bacteria
could survive on Venus,
but it's not hard to imagine how the similar
environment in Venus's clouds
might harbor some forms of life.
After all, Venus wasn't always the pressurized oven
that we know today with surface temperatures
hot enough to melt lead,
and pressures 90 times greater than the sea level on earth.
If you rewound about two billion years,
patterns on Venus's surface suggest the planet
once harbored vast oceans.
And those may have spawned life in the early solar system.
And perhaps, that life found a safe haven
in the cooler acidic clouds,
long after Venus became the sauna from hell
that we know today.
Now, scientists aren't saying
there's definitely life on Venus.
- [Narrator] But as more non-biology explanations
are ruled out,
a biological answer still looms on the horizon.
- [Narrator] Ultimately, solving this mystery will require,
you guessed it, a trip to Venus.
But right now, NASA has set it's sights
on more distant water worlds, like Europa and Enceladus.
But, you know, maybe one day we will pop over next door,
and see if anyone's home.
(mysterious music)
So what are your burning questions about space?
What would you say to a Venusian microorganism
if you met them?
Let us know in the comments below.