Kind: captions
Language: en
All right. So, let's go back back out to
space a little bit. Let's go to
the red planet
>> because we are recording this on
September 10th,
>> right?
>> And there has been an announcement from
NASA. And let me read this. It's a
quote.
>> Yeah.
Just a few hours ago, NASA had a big
press conference saying they've
discovered what, I quote,
very well could be the clearest sign of
life that we've ever found on Mars.
>> Let me catch my breath.
>> Yeah, take a deep one,
>> bro. Seriously, like clearest sign of
that is those are
>> clearest sign of life. Like I would be
happy with a sign of life.
Mhm.
>> There are pictures.
>> Yeah.
>> Right. What NASA points out in this
image is something called a leopard
spot. They circle this rock and say
leopard spot. So,
>> I'm guessing they're not saying that
>> a leopard spot fell off a leopard on
Mars and now it's right here on the
ground, right? It's some sort of mineral
signature. So, what what is going on
with the leopard spot that seems to make
it the clearest sign of life yet?
>> Yeah. Yeah. So understandably NASA
scientists like the rest of us, you
know, we give these things nicknames.
And so if you look at the photo, you can
see that it's got these speckles, right?
And it kind of looks like the spots on a
leopard.
>> And this is it looks like a sediment
deposit with different kinds of minerals
sort of sprinkled in there, if you will.
>> And what's really exciting is that those
minerals have very different chemical
properties. And so on Earth, you don't
usually find them next to one another
unless some microbe has been involved.
>> Oh,
>> and I want to underline the word
usually.
>> Usually, right?
>> So, this I would not read this as a
smoking gun that there was a microbe.
But what it does suggest is that like
here on Earth when we see these
different kinds of minerals side by side
that chances are there's some microbe
that did this. And in the case of Mars,
there was a microbe that did this in the
past and this became preserved in this
sediment. That's what's exciting. That's
why the NASA scientists who are
publishing these data are like this
smacks a bit of what we see microbes
doing on Earth.
>> So in this particular sample that NASA
has produced.
>> Yeah. Um,
why
is it that them being in proximity
I get it that
>> they're in proximity, but why does life
put them next to each other versus a
non-living scenario?
>> Yeah. One of the things that uh well,
you know, I've been alluding to is this
idea of life out of disequilibrium and
disequilibrium from the environment.
What I mean by that is we know for
example that there are microbes on earth
that uh in the deep ocean sediments
>> when you get a few centimeters or a
meter or so into the ocean sediments
oxygen's gone.
>> Okay?
>> So it's all there's no oxygen dioxygen,
right? There's no oxygen gas dissolved
in the water.
>> In many of those places there's iron
oxides, just call it rust generically
speaking. Different forms of it, right?
But there are microbes that can take
that rust and they can breathe it the
way you and I use oxygen gas. They will
breathe that rust through a really cool
process.
>> And in so doing, they will produce non-
rusty iron or iron too,
>> right?
>> And that's often soluble, but sometimes
it reacts with with elements. And I have
a buddy Brandy Toner in Mrs. Doda. She
loves this stuff. She's good at it. And
what she does is uses really cool probes
at a like the synretron facilities,
these places where we can like zap
things.
>> And she looks for different mineral
phases. And if you've got a rust sitting
next to a non- rust,
>> it's unless it's in a specific place
like a vent, right? If you've got that
sitting in deep sea sediments, there's a
good chance a microbe did that.
>> Oh, it's kind of like with uranium
decaying into lead. Yes. You see this?
>> Right. And so this particular
combination smacks of some microbe
breathing this oxide and turning it into
making this iron too. That's why the
Mars the lead scientists were excited
>> because this is we see bits of this on
Earth. Right.
>> Right. So for for these particular
minerals that they found on Mars. Where
do we find the same minerals side by
side on Earth?
>> Yeah. It's like it's again it's the same
it's underwater um hot springs. It's
deep sea sediments. Right. They're iron
containing minerals and they're it looks
like a microbe could have been breathing
one and producing the air.
>> So, does it is it always deep sea?
Because on Mars,
>> uh Jezro crater is sort of like a
>> my understanding has like a river delta
type situation where water was flowing
into a crater lake.
>> Yeah, great question. It's not always
deep sea, but the reason on Earth it's
often deep sea is because we have this
atmosphere full of oxygen. And the
moment a microbe on the surface takes
say rust and turns it into this non-
rusty iron 2 atmospheric oxygen messes
with it.
>> Right. Right.
>> Does that make sense? That does make
sense. So so this so this signature is
more likely to have occurred before we
had oxygen in our atmosphere
>> or today an anoxic
>> an anoxic environment like underneath
the sand
>> because you build up that rust uh on the
seafloor. It gets stuck in an anoxic
environment and then a microbe messes
with it. Right.
>> Yeah. So, here's what I think is cool.
Here's where I agree with NASA.
>> This leans towards something less usual.
Unusual. It's something unusual.
>> And so, it means that these minerals uh
which are Vivianite and Griite, if I
remember correctly, the fact that
they're near each other is similar to
what we see here on Earth. So, it's a
it's it's sort of um circumstantial
>> circumstantial
>> evidence, but it's cool.
>> Yeah. Yeah.
>> It's a good place to look.
>> Yeah. Yeah, it's a step in the in the in
the direction of finding life,
>> right?