December 20, 2018 • 36 mins
What do we know about life on Mars?
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Speaker 1 (00:06):
Hey, Daniel, let's talk about life. Yeah. One of the
most interesting mysteries about life is how did he get started?
I mean, how do you go from like a pile
of rocks and water and all sorts of energy to
things that actually live and turn into you know, people
and hamsters. Even more interesting is the question where did
life get Yeah, we don't even know whether life started
(00:28):
on Earth. I mean, life could have started somewhere else
in the universe and then landed here on Earth. We
could all be aliens, that's right. This is the science
fiction novel where the twist is that we are all
the aliens. But it's a deep question not just how
did life begin, but where did it begin first? And
(00:48):
it's not guaranteed that just because this life on Earth
now that it means that life started on Earth. Him
(01:10):
and I'm Daniel, and this is our podcast Daniel and
Jorge explained the universe, in which we take the whole universe,
find one interesting little nugget and try to explain it
to you in a way that you could actually understand.
No jargon, no handwaving, because it's a podcast, just actual
understandable explanations. We can press it down to thirty five minutes,
thirty minutes and then stick it in your ear downloaded
(01:33):
directly into your brain. On the episode today, we're going
to talk about is there or was there ever life
on Mars? I love this question because it's like Mars
is the other laboratory for life. You know, we all
know this life on Earth. It's a deep question about
how did life start on Earth? And when did it
(01:54):
start on Earth? And how do you start from like
a pool of water with molecules in it and lightning
and get to life? Right? But the other question is
like does it happen elsewhere? Right? If you have similar
conditions somewhere else nearby, like the next door planet, then
you can ask like did it happen there as well? Yeah?
Are we the only planet in our Solar system or
(02:15):
even the universe who has lives? Lives? Lives? Life? Does Mars?
Even how a life it stays in the weekends? Mars
turns out to be pretty dull. Ye. Now, we're not
interested in Mars is social life. We're interested in was
there ever life on Mars? And is there life on Mars? Today?
And it's a deep question because it will tell us
(02:36):
a lot about how life starts and what the chances
are for life to start if you have the basic ingredients.
You mean, we could have neighbors right now looking at us.
There could be right now life on Mars. Yeah. Oops,
I just spoiled the answer to the whole podcast. They're
probably not looking at us, but there may very well
be life on Mars today. Whether it came from Earth,
(03:00):
or whether it started on Mars, or whether life staro
Mars and then came to Earth all open questions. So
this is a big question and it's pretty ingraining in
our popular culture. You know, Martians, little green men, aliens
from Mars, and so we wanted to know if you
guys out there knew with the answer to this question
whether there is life on Mars. Yeah. So before you
(03:21):
hear these answers, think to yourself, what do you know
about life on Mars? What do you believe or what
do you hope for life on Mars. I went out
and I asked random people on the UC Irvine campus
what they thought about this question. Um, I think it's possible.
It's possible. Ye could be if you know that water
has been found, um, not like human beings. Possibly, yes,
(03:46):
what kind of life do you measure even like bacteria. Even, yes,
I think it's possible. I believe like even if you've
never seen it or discoverd it doesn't mean it doesn't
mean like it doesn't exist. Right, So most people said maybe, right, Yeah,
most people are pretty open to the idea. You know,
they thought that probably is life on Mars. They know
(04:07):
that there's water on Mars. So the takeaway here is
that NASA has done an excellent job with their pr
you know, they spend billions of dollars, they make these discoveries,
and they educate the public about it. Right, everybody has
heard about these discoveries they've made about discovering water on Mars. Yeah.
People are just captivated about this idea, right, Like they
just have to say Mars or we're going to Mars,
(04:27):
or there's water on Mars, and people just kind of
instantly pay attention. Yeah, absolutely, because it's right there. You know,
the idea of aliens being alive somewhere in the universe
is fascinating, but it's kind of remote. You know, it's distant, like, yeah, okay,
maybe there's life around Alpha Centauri or some other crazy galaxy.
You can talk about that in the abstract, but they're
so far away they will never get here, right, it
(04:48):
doesn't really matter. But if there's life on Mars, I mean,
Mars is a hop, skip and a jump away, right,
it's it's it's a few months to get to Mars.
So life on Mars we could actually go there and
we could study it. They could come here. It's an
amazing opportunity to learn about life. It's real, it's close by.
I mean you're assuming they haven't been here already, that's right.
(05:08):
It could be there are Martians among us. Maybe you're
the Martian, right, maybe martial. Maybe we're all Martians. I
am yeah, I am a Martian. I am totally just
like Matt Damon in that movie. You know. As a
note about the Martian, I heard that a huge fraction
of people who saw the movie the Martian thought it
was a documentary. No, I thought it really happened, and
they were pretty disappointed when they discovered what that's science fiction. Wow,
(05:32):
that's amazing. For all the people do know about Mars,
you know that there's water on, etcetera. They seem to
have the impression that we have the capability to go
there today, which certainly is not the case. It's a
big testament to that story and that movie is that
everything was sort of based on real science, right. I
mean all of the technology about getting there and living there,
it's all sort of available technology. That was kind of amazing.
(05:53):
You look like Matt Damon also, actually do you mean
to tell you that? Yeah? Or maybe Matt Damon is
the Martian version of me. That's right, Yeah, Matt Damon
is the Martian horn Hite child. I'm sure he tells
that to everybody, right, That's that's how he introduces themselves.
I'm sure. Yeah, Yeah, there's that fascination with Mars. I
guess it's just kind of our next door neighbor, right,
(06:15):
it's sort of the next planet over. That's not you know,
boiling for being to flow to the Sun. It's just
like the next one over. Yeah, And people have been
looking at Mars for a while because it's so close
and so, you know, telescopes became more available. People started
pointing them at Mars, and pretty early on they saw
some interesting stuff, which led to crazy speculation. You know,
people saw lines on Mars that corresponded to what they
(06:36):
thought were canals, which they thought was evidence of like civilization.
And that's pretty exciting, right, And I like to imagine
what was it like to be those people. You're you know,
you're looking at the neighboring planet for the first time.
You could see anything, right, you could see like huge
civilizations and airships and all sorts of crazy stuff, or
you could see nothing but dust and rubble. I mean
(06:56):
that moment when you first get get a bide at
a scientific apples really exciting time. And so for them
to look through those telescopes and see something that looks
like civilization, that must have been pretty exciting. Yeah. I mean,
it's maybe something a lot of people don't know, is
that you can go out in a typical night and
look out into the sky and see Mars like you
can see the next planet over. Yeah. Yeah, And not
(07:18):
only can you see you can see its color. Right,
It's not just like a tiny dot in the sky.
You could see it's reddish, like you are seeing the
surface of another planet. It's incredible. Yeah, that's amazing. So
I thought, before we would dig into this idea of
life and Mars, I thought it'd be cool to just
kind of um talk a little bit about some facts
about Mars. So it did some extensive research online or
(07:40):
does that mean you just looked at Wikipedia. Yeah, uh, well,
I thought it was cool that Mars is about only
about half of the diameter of Earth. It's actually smaller
than Earth, like we are the bigger brother. Yeah, it
got a small scoop of planet stuff. Yeah, that makes
it a lot smaller. And that has consequences because it
means that the gravity on Mars is us Right, you
stand on surface of Mars. That's basically an instant diet
(08:03):
right there. Yeah, you'll weigh less, you can jump, you
can jump higher. Yeah, you can stand on Mars and
eat Mars bars and still you can eat twice as
many um. But it's not just because it's smaller. It's
also less dense, Like it's a planet. It's half the
size of the Earth, but the planet itself, like the rock,
(08:24):
it's less dense. Yeah, it's like fluffier. Yeah, it's fluffier. Yeah. Yeah.
I think that must be connected, right, because the more
stuff there is, the more gravity there is, the more
it gets compressed. Like the interior of the Sun must
be denser than the interior of Jupiter, which must be
denser than the interior of the Earth. Right, So I
think there must be a connection between the size of
the planet and the density of the interior. Oh right, Yeah,
(08:47):
And another interesting fact that read was that Mars does
have an atmosphere. You can go there and there's wind
and there's an atmosphere around it, but it's only about
one percent of the atmosphere we have here. Try. Yeah,
Mars does not have much of an atmosphere, which is
pretty important for supporting life. Yeah, okay, And the last
cool fact I read was that a day on Mars, like,
(09:08):
if you're standing on Mars, a day for you would
last one day in thirty seven minutes. That's right. That's
sounded kind of amazing to me, because you know, the
length of the day on the planet is just determined
by how fast it spins. And you know, these planets
could spin at any speed, and so the fact that
it lasts just about an Earth day, it's spinning it
just about the same speed it's the Earth, right, And
(09:30):
it turns out a lot of the planets you're spinning
it at approximately the same speed. We all sort of
spun out at the same rate. Yeah, but does that
make you like want to go to Mars and imagine
you'll get like an extra few minutes every day. Well,
not only would you weigh less, you would have some
extra climb in your hand every day. Imagine what you
can do with an extra thirty seven minutes every day. Yeah,
the commute, the like nine months each way commute might
(09:52):
be kind of killer though, but no traffic, right, Sometimes
I feel like I'm on the four or five for
nine months anyway. So if you're like, might as well
go to Mars, you know. Cool. So that's that's our
sister planet, and it's sort of the same size. It's
very close by were blue, Mars is red, So there's
sort of the interesting parallel that people think about, right, Yeah,
(10:13):
if you think about where life can exist in the universe,
there are these little slices. You know, you have to
be a certain distance from the Sun in order to
not be broiled on the surface, right, but you can't
be too far away. It's because you can't be too cold.
You have to have liquid water, and so there's these
narrow regions around each star. They call it the habitable
zone where liquid water can exist on the surface, and
(10:34):
Earth certainly in it. And Mars is right there, you know,
like there's not that much in the Solar System. Aren't
that many planets inhabitable zone, and so Mars is a
great candidate. Yeah, so it's it's sort of it's warm
and bombing, and it's not sort of extreme like some
of these other planets, right, Like, if you go to
Venus or Mercury or Jupiter, you would just die instantly.
What don't you that's right. I wouldn't call Mars warm
(10:55):
and bombing unless you have in charge of the advertising
for Martian vacations. It's definitely cold, Okay, Mars is sub freezing, right,
package jacket folks, and don't bring your swimsuit because Mars
is subfreezing. But on the scale of like you know,
Pluto or Jupiter or whatever, it's definitely warm and bomby.
So from that perspective, I think we're legally allowed to
say that. What I mean is that we can imagine
(11:18):
ourselves being there and visiting and not dying instantly. Absolutely,
humans with appropriate life support could exist on the surface
of Mars. What's fascinating is that the service of Mars
today is cold and sub freezing and very thin atmosphere.
But it didn't used to be that way. In fact,
Mars a long time ago used to be much more
(11:38):
like Earth. It used to be a you know, it
would be an excellent candidate for life billions of years ago. Wow, Okay,
let's hear more about that. But first let's take a
quick break. So you're saying that at some point Mars
(12:03):
was a lot different than it is now, like it
was more hospitable to life, Like it was actually sort
of more closer to what Earth looks like. Now, that's right.
We think based on evidence we see on the surface
of Mars now, you know, like the way the rocks
look and and the geological patterns, that Mars used to
be much more like Earth, almost covered with oceans like
(12:24):
there used to be huge amounts of liquid water on
the surface of Mars. Estimates vary from between thirty to
seventy of the surface of Mars used to be covered
in water like Us, just like Earth. Right, So Mars
would have been kind of a blue planet, not a
red planet, billions of years ago. And in addition, it
had a rich atmosphere much more than it does today.
(12:45):
And the atmosphere is key because an atmosphere is like
a blanket for a planet. I mean, you know that
emitting gases into our atmosphere is what's causing global warming. Well,
if you don't have any atmosphere at all, you can't
keep any heat near the surface. So you need some
sort of atmosphere just to trap the sunlight, you know,
to accumulate some heat and to prevent yourself from being
basically as cold as outer space. To Mars a long
(13:05):
time ago had a pretty robust atmosphere, which meant the
surface temperature was enough for liquid water, for example. So
that's a big difference. It just had this thin layer
of gas and that sort of protects acts like a shield,
like a bubble that lets you have liquid water on
the surface. Yeah, and it protects you against a lot
of stuff. Not only does it keep you warm, but
(13:25):
it prevents impacts from asteroids and meteors and stuff like that,
because when they hit the Earth, it's sort of like
an elfin hitting a water bed or something. It creates
a big splash in the atmosphere instead of getting all
the way down to the ground, right, and it probably
hurts too. Yeah. I think elephants like jumping on water
and what you're talking about. UM, But no, atmospheres are
very important, UM. For sustaining life, I mean life needs
(13:48):
to breathe, right, and also for keeping the temperature warm
enough and for protecting yourself against impact from from rocks
from space. So so marts you usually have these huge
oceans and sort of an atmosphere is like we do,
probably clouds, you know, beaches, um. So that's why we
think that maybe there could have been life. That's right,
as far as we know from a biological point of view, right,
(14:09):
what does it take to make life? Well, it takes
basic organic molecules, and those exist on Mars today, so
we're sure that they existed a long time ago. It
takes liquid water, right, it takes an energy source meaning
the sun um. And we don't really know what else
it takes. I mean, you can't have too many toxins,
you can't be blasted by radiation. Um. But we don't
(14:31):
really know. The deep question about in biology right now
is if you have all that stuff and you let
it sort of smooth around for millions of years or
billions of years, how often do you get life? You know,
is it one in a trillion, or is it every
other time? Or is it Planets that have that condition
eventually get microbial life we just don't know the answer.
(14:51):
It's like somebody makes the same ingredients we had here
in Earth, and the question is did little micro's pop
up in the middle of it? That's right, and you know,
my instinct is that it must have. And one piece
of evidence we have is that on Earth, it seems
like life started pretty soon after those conditions formed. You know,
once we had an atmosphere and the liquid water and
the temperature is about right, it didn't take very long
(15:12):
for life to start. So that suggests that it's not
like a one in a bazillion chance and millions of
years you suggests that, you know, it's likely to happen. Yeah,
think about all the molecules in an ocean, right, all
the organic molecules bumping against each other. You might think
it's so improbable for it to bump into each other
and form RNA and that something that would happen to
(15:33):
be self replicating and build from there. Yeah, it's improbable,
but you've got tend to the you know, huge number
of atoms bumping against each other for millions of years.
That's a lot of tries, right. If it's like you know,
monkeys on a typewriter banging away. Eventually one of them
is going to produce Hamlet. Yeah, it's a good picture
of of of a creator for the universe. Get a
(15:54):
bunch of monkeys banging molecules around. Oh look, i'mde Dna,
the creator. Sometimes it does seem like a like an
idiot monkey. Yeah, I agree. Welcome to blasphemy by Jorhand Daniel.
So that's kind of why we think that maybe there
could have been life because it looked just like the Earth.
It had the right conditions, but then all of that
(16:15):
went away at some point because the Mars we see
now it looks like a big, big old desert. Yeah,
that's why we think that Mars was a great laboratory
for answering this question. Right, If life existed on Mars
billions of years ago, when the conditions were great, that
tells you a lot about the chances for life to start.
If life didn't exist on Mars billions of years ago,
that tells you a lot about the chances for life
(16:37):
to start. Right. But as we alluded earlier in the podcast,
we don't actually know if life started on Mars or
life started on Earth. Right, it could have started in
either place. We should talk about that before we talk
about the great disaster of Mars. You mean, like, so
Mars used to look like Earth. Maybe life started there
and somehow made it over here exactly, And so you
(17:00):
might be thinking, Hold at a second, how could microbial
life like build a spaceship, launch it and come over
to Earth. That's ridiculous, right, Why is that ridiculous? Well,
I don't know. Bacteria don't seem to build technology, or
develop space ships or launched themselves into space very often.
I mean, not that we're aware of. Bacteria are secretly
exploring the universe. We don't little tiny rocket ships. Yeah,
(17:22):
but actually it happens, and it happens sort of accidentally.
And the way it happens is that you could have
like a piece of life, you know, a little bit
of bacteria on a rock, and that rock you get
knocked into space by the impact of an asteroid. So
you know, rock number one, come from space, blast onto
the plane, a huge explosion. Stuff flies everywhere. Some of
(17:42):
that stuff flies into outer space. Right. You can knock
a rock off the surface of a planet if you
hit it hard enough, and it would just go out
into space, float around the Solar System and land in
our planet. Yeah, and not all of them, of course,
would land on our planet. Most of them would just
float in space forever. But occasionally some of them will it.
And we know that this happens, like, for a fact,
(18:03):
we have rocks that we found on Earth that we
are sure came from Mars, so we know that this
is a thing. Wait, how do how do we know
they're from Mars? Do they have a little like a
made in Mars? It's the return postmark. Of course, it's
not so complicated. Um No, we can look at it,
the chemistry of it and the geology of it, and
they're just totally different from Earth rocks, and there's completely
(18:23):
consistent with what we think Mars rocks look like. And
you know, we've sent um robots to Mars. We've studied them,
so we know something about Martian geology and these rocks
just could not have formed on Earth and they're totally
consistent with rocks forming on Mars. So we have in
our labs rocks from Mars, right Like, we haven't been there,
but we already have pieces of it. So it's possible
(18:45):
that maybe you know, there was a little microbe who
went to sleep at night in his little rock or
her rock home. Something happened and the next day here
she woke up on Earth. Yeah that's right, probably the
next thousands of years. But you know, and microbes can
live along time and they can just go to sleep,
and a lot of them can survive crazy things. I mean,
there are microbes living on the outside of the International
(19:07):
Space Station right now. It's almost impossible to eradicate all
life from anything. I mean, you zap it with radiation,
you'll find a few microbes that are radiation hard. You
heat them up. You'll find some microbes that really like
it hot and dry them out. You'll find microbes that
can live in dry environments. It's crazy. So someone could
have survived the impact of an asteroid thrown into space,
(19:29):
surviving the cold and vacuum, survived the entry into Earth,
and then come out and be like, hey, this is
my new house. That's right. That thing has a great backstory.
Let me tell you there was a moment about what
is it now, twenty years ago when NASA thought they
actually had discovered evidence of life from a Martian rock,
right like a rock that came from Mars with evidence
(19:50):
of life in it. This was a pretty exciting moment.
People freaked out. Yeah, because NASA went and gave a
press release and said, we have this rock we're pretty
sure came from Mars, and when we cut it open,
we found these things in it that we think could
only be explained by life. They were these tiny little
shapes that looked like bacteria. They were much smaller than
Earth bacteria, but you know, you could imagine maybe this
(20:13):
is what life looks like on Mars. And so they
were pretty excited about it. But then what happened They
discovered that it was not actually microft tracks. Yeah. Well,
the scientists who suggested it, they still believed that it
was evidence for life, and to them it was the
most compelling story. But you know, in science, a pretty
big claim requires pretty big evidence, right, And so other
(20:34):
people dug into it and they came up with explanations
for how you could form those shapes using non organic
um processes, you know, just geological processes. Crystal formation could
give you this, and this kind of geology could give
you that, and so the rock could just naturally have
these formations. Yeah, they found plausible ways to make the
same thing without having to have microbial life. Yeah, which
(20:56):
is a bit of a bummer. It's a bummer that
we're not Martians. Well, it's a bum to not have
discovered life on Mars. I mean, that would be an
incredible moment, right to know that there was life on
another planet. But of course it still wouldn't answer the question.
Even if you found a rock with life from Mars
on it, you still wouldn't know did life come to
Earth from Mars, because then you've established that there's a
transport mechanism, or did it start on Earth and then
(21:19):
go to Mars and then come back, right, It wouldn't
answer that question. Yeah, but there's still also just the possibility.
I mean, they've proven that you can make these formations
some other ways, but that doesn't mean that necessarily that
those were not made by microbes. Right. It could be
that we're looking at evidence of life on Mars. We
just can't prove it, right, That's the problem is. And
before you're going to accept that, you really got to
(21:40):
have pretty solid evidence. You've gotta have something which is
unique to life, right, And so before you're going to
believe that there really is life or was life on Mars,
I think you gotta really see it. You gotta get there.
You gotta get some in your hands. You gotta life,
you know, play with it, see it move. You gotta
really be convinced. Chickens papers. Make sure it came from
birth certificate, you know, social Security number exactly. So we
(22:08):
think there might have been life on Mars a long, long
long time ago, right, And Mars used to look really different. Yeah,
it was more fertile, it was more sort of prone
to have life, that's right. Yeah it was. It was
a happy place to be, but not anymore. And the
thing that happened is that Mars lost its atmosphere. Something
happened that made it all sort of proof away. Yeah.
The atmosphere, the thing that would keep the surface warm
(22:31):
and have to have liquid water and you know, provide
the nutrients that life would need. That atmosphere got blown
away by the solar wind. See, on Earth, we have
an atmosphere, and our atmosphere is protected from the solar wind.
The solar wind is just like a huge flow of
radiation from the Sun. The thing that protects us from
the solar wind is our magnetic field, right. Mostly the
(22:52):
solar wind is charged particles being shot at us from
the Sun. But charged particles get bent in magnetic field,
and so our magnetic field mostly deflects them, and some
of them spiral down. And that's what you see in
the northern lights, right, is all these charged particles hitting
the atmosphere. It's like the Sun is shooting a giant
death ray at us. But we have some sort of
force field basically, right, we have like a special force
(23:12):
field that deflects it. Yeah. Literally, the Sun is the
death Star's fully operational and it's blasting us all the time.
And if we didn't have the magnetic field, then yeah,
we'd be in trouble because it would slowly eat away
at our atmosphere, would just strip it away, which is
blast walled our oxygen and air, and we'll be totally
(23:33):
exposed to those rates exactly, and then the temperature on
Earth would plummet and all of that stuff. And that's
what happened to Mars. We don't know why, just like
we don't have a great understanding of why Earth has
a magnetic field and why it flips. And you know,
we should do a podcast on that another time. But Mars,
we think had a magnetic field, which is why it
had an atmosphere, and then it lost it and it
might have been that it just cooled down and whatever
(23:55):
was happening inside Mars that you know, gyro magnetism that
created the magnetic field inside Mars just sort of stopped
and it lost its magnetic field, which means it lost
its its shield from the death star, which means it
lost its atmosphere dot dot dot, and then it got
blasted by the death ray from the Sun. And it
is what it is today, which is pretty barren and inhospitable, right, yeah,
(24:17):
And so it has an atmosphere today like you were saying,
but it's really thin, right. There's hardly any gas surrounding Mars,
so there's not enough to keep the surface warm. Right,
So if you go to Mars today, you wouldn't recognize
it from billions of years ago. You know, if if
life started on Mars and came to Earth and then
wanted to go home, it would be like, this is
not the Mars. I know, what have you done? Who
(24:38):
turned off the magnetic field? No, it's totally it's a
post apocalyptic healthscape I'm compared to what it used to
look like. But there could still be life there now, right,
That's right. We have not ruled out the possibility that
there could still be somehow life surviving on the surface, because,
as we said earlier, life finds a way to survive.
You know, once you have a planet that's just covered
(25:01):
in gazillions of microbes, they have a huge diversity, and
even in an enormous cataclysm, it's almost impossible to wipe
them out completely. Some of them will survive. And so
even though Mars lost its its magnetic field, it may
mean that there's no more life on the surface, right,
because it's no more liquid water on the surface, But
there could still be life on Mars. Right. What does
life need? It needs water, it needs nutrients, it needs um,
(25:24):
you know, not a whole lot of toxins. It needs
protection from radiation, some sort of a heat source, right,
A little bit of warmth, yeah, a little bit of warmth,
but you know, not too much, just enough to have
your water be liquid basically, and you know, a huge
caveat Somebody out there is probably thinking, hold on a second,
they're just talking about Earth like life, right, life like
it lived, like it exists on Earth. Whoever, you are
(25:46):
out there driving in your car thinking that we're totally crazy,
You're right, We're talking about Earth like life, because that's
the only life we know, and there's a possibility that
life could exist in completely different forms, you know, that
doesn't require liquid water and operates on geology called time
scales and frozen water. But you know, we're gonna have
to put that aside because it's so alien we can't
even really explore it or consider it or discover it. Right,
(26:08):
So for now, let's just think about earthlike life. Yeah, well,
let's talk about what we know about Mars and what
we can see today. But first let's take a quick break, okay, Daniel,
(26:30):
So what do we know about Mars today? Like, what
can we see that might lead us to believe there
are microbes or maybe little green men hiding hiding under
the surface that we can't see. Oh I wish they
were a little green men hiding onto the surface of Mars.
That would be amazing, right, what a discovery that would be. Well,
I know there's robots on the surface of Mars. There
are a few robots driving around Mars, but those are
(26:50):
Earth robots, Um there are I love these cartoons that
show like little green men hiding behind rocks to the
cameras from the rowers, right, like they're there, they're just
camera shy, yeah exactly. But you know, we have more
than just robots driving on the surface. We also have
satellites orbiting Mars and imaging surface and comparing the picture
today to yesterday. And so we're looking, Yeah, we're looking
(27:13):
if anything moved on the surface of Mars, and we
would notice, you know, it would not be hard to
spot some sort of activity. So we don't see any
movement or structures built by any civilizations or it just
looks like a big red rock. Yeah. What we see
our structures that look like you know, water flow canals
and geological formations, and so there's some activity on Mars,
(27:34):
but none of it seems to be like due to life. Absolutely.
So there's no large macroscopic life on Mars, which is
a bummer, you know, because that would have been awesome.
Um and you know, maybe Martian scientists could have tossed
the secrets of the universe, but that's not in the cards,
right that we can see, Right, that's kind of key.
On the surface, there aren't any that we can see.
(27:54):
But but it's hard to imagine though, like a technological
civilization living under the surface of Mars, and no presence
on the surface. I mean, imagine that was you. Right,
you have a civilization on the surface of Mars. It's thriving,
it's exciting. You know, life is good. You have you know,
fun plans on the weekend. All of a sudden, you
lose your magnetic field. The atmosphere starts stripping away, the
temperatures plummeting. You decided to go underground. Right, Still, you're
(28:16):
gonna want to have something on the surface to collect,
like solar power or something. Right, You're gonna leave some
evidence on the surface of the fact that we used
to be there. We see nothing, just natural rock. Yeah,
it's a fun concept for somebody's science fiction novel that
there could be today technological civilizations on the inside of Mars.
But I put it on a pretty low probability. Um,
(28:37):
but there is the possibility that microbial life could have
survived underground, so there could be an inside of the
rock instead of the dirt in Mars. There could be little,
little green microbes. Yeah. And the reason that we think
that the real possibility is that NASA has discovered water
on Mars. Liquid water, so not on the surface, because
(28:59):
on the surface is so cold that if you like
if you spat it would freeze in a crystal before
it hit the ground, right or evaporate right or evaporate
probably is probably more more realistic. But under the ground
it's warmer and it's protected from you know, all sorts
of radiation, etcetera, etcetera. And they found evidence of a lake,
huge lake of liquid water underground. But it's like a
(29:20):
mile underground. It's not like just under the surface. It's deep,
deep underground. How did they see it? How did they
know it's there? Yeah, they can see it by studying,
by using radar, I think. So they have ground penetrating
radar and all sorts of clever stuff to see what's
under the rock. So there could be like martian dolphins
swimming around in there in these caves. It'd be pretty dark.
(29:41):
I don't know how dolphins would survive and what they
would eat. I think much more likely is that there's
martian microbes right whatever. However, life started billions of years
ago could have survived on Mars. In turn, in these
lakes that are underground. Because there's liquid water, the ground
itself protects them from the radiation of the sun right
at the prays and so as long as they can
(30:02):
find some nutrients. And um, you know my wife, she's
a biochemist. She's always telling me that microbes can eat anything. Right,
there's nothing, no situation in which microbes can't find something
to extract energy from. Right. It's the opposite of children.
They won't eat anything. That's why I keep telling it.
We should have had microbes for kids and feed if
(30:25):
only I know, I know. Um. And there's also other
exciting information, like we actually have some clues that suggest
that there's life on Mars, not just the possibility. Oh
there's water, so there further could be there are other
things you can do look for life on Mars, which
is to look for biomarkers. Like if life exists, then
it has to have some sort of metabolism. Right, there's
(30:45):
like a process there. You know, it's eating something, it's
pooping something like their breath. Yeah there, yeah, exactly. And
so what we've done is we've looked at the atmosphere
of Mars and we've seen methane in the atmosphere. The
methane is not long lived, and so if you see
in the atmosphere, it means it was produced fairly recently.
But I mean it's not long lived like it it
goes away and it disappears. It breaks down. Yeah, it's
(31:08):
not stable. It breaks down the atmosphere under under sunlight
interaction with other things. Now, so we see these sort
of clouds methane appear and then they break down. So
something must be making this methane. Yeah, And there's some
explanations just you know that are that don't involve life,
like volcanic activity or whatever whatever. But the interesting thing
is that the methane produced on Mars varies with the seasons,
(31:30):
and so like you know, it's more in one season
and less in another season. Like you know, it's a
lot more in the summer and less in the winter.
And that suggests it's very suggestive of some sort of
biological process, right, as these things like sleep during the
winter and then wake up in the summer and eat
and fart a lot, because man, that's what methane is, right.
You'd be there and be like, m hmm, it's farting season.
(31:53):
Somehow in this podcast we always end up coming back
to farts. We should have called this for podcast farts
in science. Yeah, but our farts Mars called Mars. They're
called farshions. Um, so that's pretty tantalizing evidence, right, That
sells there's something going on that produces methane on a
seasonal scale. And it could just be volcanic activity that's
(32:14):
triggered by the Sun. There are some it could be
Mars itself, it's farting. It could be like the planet
is farting, like releasing we are smelling Mars's buttle exactly.
That could be the scenario. I think he went too farther.
I think they might have to edit that one out. Well.
I like this idea that you brought up the other day,
(32:36):
which is that, um, you know, we're sending these robots
to Mars, and you know, we try to clean in
them and clean them and disinfect them, but it could
be that we're accidentally sending life to Mars with these robots. Yeah,
almost certainly actually, because it's almost impossible to completely clean something.
Right you build on Earth, it's going to be covered
in Earth microups. I mean, they developed like special sprays
(32:58):
to disinfect this stuff, like super kill everything sprays, and
they sprayed on these satellites and then they discover, oh,
there's a kind of bug on these satellites that eats
that spread. It's like, I'm young, give me more, right,
So it's it's and you can shoot it with radiation.
You can do everything you like. It's almost impossible, which
means that when we send something to Mars, these rovers,
(33:20):
we are sending life to Mars. So is there life
on Mars? Well, almost certainly an earth microbe was sent there. Yes,
did it survive? Could it? Could it reproduce? Has it
like tainted Mars is going to colonize Mars and by
the time we get over there, it's gonna be covered
in Earth microbes. I don't think so, but you know
we It sort of muddles the question. And it's actually
zones on Mars where you're not allowed to send probes
(33:42):
because they're trying to keep it free from contamination. Wow.
So that's a huge twist. I mean, the answer to
the question is their life and Mars. You would think
it would be no, but the answer is yes, and
we put it there. I don't know that we can
say confidently if there are microbes on the surface of
those rovers, but I wouldn't bet against it. Yeah, I
wouldn't bet against it. So let me get to say
this is a total possibility life started on Mars a
(34:04):
long time ago, came to Earth through some freak asteroid accident,
evolved into us. We build robots and rocket chips, and
they put life back on Mars after there was this
apocalypse there. Yeah, and maybe that was their whole plan.
They saw this apocalypse coming and they're like, let's ride
a rock to Earth and then come back in a
billion years, you know, return to Mars. That's the title
(34:26):
of the sci fi novel we're writing. Yeah, And I
just think it's a fascinating question. And if we could
find microbs on Mars, I mean, say we send people
over there, or we get a sample of it, we
dig down a mile to even get a sample and
bring it back, then we could start to answer some
really interesting questions just by studying that life, right, Like,
is it um, RNA and DNA based the way our
(34:46):
life is? Is it similar? If it was totally different,
completely biochemically different, Wow, that would be fascinating because it
would mean there's different ways to build life. If it's
the same, that means either there's only one way to
build life and it happened in parallel and from places,
or it started in one place and went to the
other and man, there's so many amazing threads that you
could unravel if we just had a sample of that
(35:08):
lake from underground on on on Mars. Well, and the
answer in all these cases would be mind blowing. Right,
we're either super unique, we were either Martians, or there
is a totally different way to make life. Yeah, and
the facts are there right like right now, there could
be microbs wiggling around on Mars. And you know, it's
not that hard to get there. We have the technology,
(35:29):
we just lacked sort of the political will. You know,
it's amazing to meet these moments when you have the
technology and all you need to do is get the money,
and you could just buy the answers to deep secrets
about the universe. Right, it cost a few billion bucks
or whatever, but we could do it. If Congress and
the President decided this is important, let's do it, that
you could do it. So we have the opportunity we
(35:50):
could buy this knowledge. We just aren't all right, Well, tonight,
if you go out there and look at the night
s guy, you know, look up in an app of
where Mars is right now, and if you can look
at it at night, so you can go out there,
grab a Mars bars, eat it and look up at
that red planet and and smell it's farts. Yeah, or
turn around and send some farts to Mars and maybe
(36:13):
maybe that's the way they communicate farts is space. On
that note, if you still have a question after listening
to all these explanations, please drop us a line. We'd
(36:35):
love to hear from you. You can find us at Facebook, Twitter,
and Instagram at Daniel and Jorge That's one word, or
email us at Feedback at Daniel and Jorge dot com.
Hey, Daniel, let's talk about life. Yeah. One of the
most interesting mysteries about life is how did he get started?
I mean, how do you go from like a pile
of rocks and water and all sorts of energy to
things that actually live and turn into you know, people
and hamsters. Even more interesting is the question where did
life get Yeah, we don't even know whether life started
(00:28):
on Earth. I mean, life could have started somewhere else
in the universe and then landed here on Earth. We
could all be aliens, that's right. This is the science
fiction novel where the twist is that we are all
the aliens. But it's a deep question not just how
did life begin, but where did it begin first? And
(00:48):
it's not guaranteed that just because this life on Earth
now that it means that life started on Earth. Him
(01:10):
and I'm Daniel, and this is our podcast Daniel and
Jorge explained the universe, in which we take the whole universe,
find one interesting little nugget and try to explain it
to you in a way that you could actually understand.
No jargon, no handwaving, because it's a podcast, just actual
understandable explanations. We can press it down to thirty five minutes,
thirty minutes and then stick it in your ear downloaded
(01:33):
directly into your brain. On the episode today, we're going
to talk about is there or was there ever life
on Mars? I love this question because it's like Mars
is the other laboratory for life. You know, we all
know this life on Earth. It's a deep question about
how did life start on Earth? And when did it
(01:54):
start on Earth? And how do you start from like
a pool of water with molecules in it and lightning
and get to life? Right? But the other question is
like does it happen elsewhere? Right? If you have similar
conditions somewhere else nearby, like the next door planet, then
you can ask like did it happen there as well? Yeah?
Are we the only planet in our Solar system or
(02:15):
even the universe who has lives? Lives? Lives? Life? Does Mars?
Even how a life it stays in the weekends? Mars
turns out to be pretty dull. Ye. Now, we're not
interested in Mars is social life. We're interested in was
there ever life on Mars? And is there life on Mars? Today?
And it's a deep question because it will tell us
(02:36):
a lot about how life starts and what the chances
are for life to start if you have the basic ingredients.
You mean, we could have neighbors right now looking at us.
There could be right now life on Mars. Yeah. Oops,
I just spoiled the answer to the whole podcast. They're
probably not looking at us, but there may very well
be life on Mars today. Whether it came from Earth,
(03:00):
or whether it started on Mars, or whether life staro
Mars and then came to Earth all open questions. So
this is a big question and it's pretty ingraining in
our popular culture. You know, Martians, little green men, aliens
from Mars, and so we wanted to know if you
guys out there knew with the answer to this question
whether there is life on Mars. Yeah. So before you
(03:21):
hear these answers, think to yourself, what do you know
about life on Mars? What do you believe or what
do you hope for life on Mars. I went out
and I asked random people on the UC Irvine campus
what they thought about this question. Um, I think it's possible.
It's possible. Ye could be if you know that water
has been found, um, not like human beings. Possibly, yes,
(03:46):
what kind of life do you measure even like bacteria. Even, yes,
I think it's possible. I believe like even if you've
never seen it or discoverd it doesn't mean it doesn't
mean like it doesn't exist. Right, So most people said maybe, right, Yeah,
most people are pretty open to the idea. You know,
they thought that probably is life on Mars. They know
(04:07):
that there's water on Mars. So the takeaway here is
that NASA has done an excellent job with their pr
you know, they spend billions of dollars, they make these discoveries,
and they educate the public about it. Right, everybody has
heard about these discoveries they've made about discovering water on Mars. Yeah.
People are just captivated about this idea, right, Like they
just have to say Mars or we're going to Mars,
(04:27):
or there's water on Mars, and people just kind of
instantly pay attention. Yeah, absolutely, because it's right there. You know,
the idea of aliens being alive somewhere in the universe
is fascinating, but it's kind of remote. You know, it's distant, like, yeah, okay,
maybe there's life around Alpha Centauri or some other crazy galaxy.
You can talk about that in the abstract, but they're
so far away they will never get here, right, it
(04:48):
doesn't really matter. But if there's life on Mars, I mean,
Mars is a hop, skip and a jump away, right,
it's it's it's a few months to get to Mars.
So life on Mars we could actually go there and
we could study it. They could come here. It's an
amazing opportunity to learn about life. It's real, it's close by.
I mean you're assuming they haven't been here already, that's right.
(05:08):
It could be there are Martians among us. Maybe you're
the Martian, right, maybe martial. Maybe we're all Martians. I
am yeah, I am a Martian. I am totally just
like Matt Damon in that movie. You know. As a
note about the Martian, I heard that a huge fraction
of people who saw the movie the Martian thought it
was a documentary. No, I thought it really happened, and
they were pretty disappointed when they discovered what that's science fiction. Wow,
(05:32):
that's amazing. For all the people do know about Mars,
you know that there's water on, etcetera. They seem to
have the impression that we have the capability to go
there today, which certainly is not the case. It's a
big testament to that story and that movie is that
everything was sort of based on real science, right. I
mean all of the technology about getting there and living there,
it's all sort of available technology. That was kind of amazing.
(05:53):
You look like Matt Damon also, actually do you mean
to tell you that? Yeah? Or maybe Matt Damon is
the Martian version of me. That's right, Yeah, Matt Damon
is the Martian horn Hite child. I'm sure he tells
that to everybody, right, That's that's how he introduces themselves.
I'm sure. Yeah, Yeah, there's that fascination with Mars. I
guess it's just kind of our next door neighbor, right,
(06:15):
it's sort of the next planet over. That's not you know,
boiling for being to flow to the Sun. It's just
like the next one over. Yeah, And people have been
looking at Mars for a while because it's so close
and so, you know, telescopes became more available. People started
pointing them at Mars, and pretty early on they saw
some interesting stuff, which led to crazy speculation. You know,
people saw lines on Mars that corresponded to what they
(06:36):
thought were canals, which they thought was evidence of like civilization.
And that's pretty exciting, right, And I like to imagine
what was it like to be those people. You're you know,
you're looking at the neighboring planet for the first time.
You could see anything, right, you could see like huge
civilizations and airships and all sorts of crazy stuff, or
you could see nothing but dust and rubble. I mean
(06:56):
that moment when you first get get a bide at
a scientific apples really exciting time. And so for them
to look through those telescopes and see something that looks
like civilization, that must have been pretty exciting. Yeah. I mean,
it's maybe something a lot of people don't know, is
that you can go out in a typical night and
look out into the sky and see Mars like you
can see the next planet over. Yeah. Yeah, And not
(07:18):
only can you see you can see its color. Right,
It's not just like a tiny dot in the sky.
You could see it's reddish, like you are seeing the
surface of another planet. It's incredible. Yeah, that's amazing. So
I thought, before we would dig into this idea of
life and Mars, I thought it'd be cool to just
kind of um talk a little bit about some facts
about Mars. So it did some extensive research online or
(07:40):
does that mean you just looked at Wikipedia. Yeah, uh, well,
I thought it was cool that Mars is about only
about half of the diameter of Earth. It's actually smaller
than Earth, like we are the bigger brother. Yeah, it
got a small scoop of planet stuff. Yeah, that makes
it a lot smaller. And that has consequences because it
means that the gravity on Mars is us Right, you
stand on surface of Mars. That's basically an instant diet
(08:03):
right there. Yeah, you'll weigh less, you can jump, you
can jump higher. Yeah, you can stand on Mars and
eat Mars bars and still you can eat twice as
many um. But it's not just because it's smaller. It's
also less dense, Like it's a planet. It's half the
size of the Earth, but the planet itself, like the rock,
(08:24):
it's less dense. Yeah, it's like fluffier. Yeah, it's fluffier. Yeah. Yeah.
I think that must be connected, right, because the more
stuff there is, the more gravity there is, the more
it gets compressed. Like the interior of the Sun must
be denser than the interior of Jupiter, which must be
denser than the interior of the Earth. Right, So I
think there must be a connection between the size of
the planet and the density of the interior. Oh right, Yeah,
(08:47):
And another interesting fact that read was that Mars does
have an atmosphere. You can go there and there's wind
and there's an atmosphere around it, but it's only about
one percent of the atmosphere we have here. Try. Yeah,
Mars does not have much of an atmosphere, which is
pretty important for supporting life. Yeah, okay, And the last
cool fact I read was that a day on Mars, like,
(09:08):
if you're standing on Mars, a day for you would
last one day in thirty seven minutes. That's right. That's
sounded kind of amazing to me, because you know, the
length of the day on the planet is just determined
by how fast it spins. And you know, these planets
could spin at any speed, and so the fact that
it lasts just about an Earth day, it's spinning it
just about the same speed it's the Earth, right, And
(09:30):
it turns out a lot of the planets you're spinning
it at approximately the same speed. We all sort of
spun out at the same rate. Yeah, but does that
make you like want to go to Mars and imagine
you'll get like an extra few minutes every day. Well,
not only would you weigh less, you would have some
extra climb in your hand every day. Imagine what you
can do with an extra thirty seven minutes every day. Yeah,
the commute, the like nine months each way commute might
(09:52):
be kind of killer though, but no traffic, right, Sometimes
I feel like I'm on the four or five for
nine months anyway. So if you're like, might as well
go to Mars, you know. Cool. So that's that's our
sister planet, and it's sort of the same size. It's
very close by were blue, Mars is red, So there's
sort of the interesting parallel that people think about, right, Yeah,
(10:13):
if you think about where life can exist in the universe,
there are these little slices. You know, you have to
be a certain distance from the Sun in order to
not be broiled on the surface, right, but you can't
be too far away. It's because you can't be too cold.
You have to have liquid water, and so there's these
narrow regions around each star. They call it the habitable
zone where liquid water can exist on the surface, and
(10:34):
Earth certainly in it. And Mars is right there, you know,
like there's not that much in the Solar System. Aren't
that many planets inhabitable zone, and so Mars is a
great candidate. Yeah, so it's it's sort of it's warm
and bombing, and it's not sort of extreme like some
of these other planets, right, Like, if you go to
Venus or Mercury or Jupiter, you would just die instantly.
What don't you that's right. I wouldn't call Mars warm
(10:55):
and bombing unless you have in charge of the advertising
for Martian vacations. It's definitely cold, Okay, Mars is sub freezing, right,
package jacket folks, and don't bring your swimsuit because Mars
is subfreezing. But on the scale of like you know,
Pluto or Jupiter or whatever, it's definitely warm and bomby.
So from that perspective, I think we're legally allowed to
say that. What I mean is that we can imagine
(11:18):
ourselves being there and visiting and not dying instantly. Absolutely,
humans with appropriate life support could exist on the surface
of Mars. What's fascinating is that the service of Mars
today is cold and sub freezing and very thin atmosphere.
But it didn't used to be that way. In fact,
Mars a long time ago used to be much more
(11:38):
like Earth. It used to be a you know, it
would be an excellent candidate for life billions of years ago. Wow, Okay,
let's hear more about that. But first let's take a
quick break. So you're saying that at some point Mars
(12:03):
was a lot different than it is now, like it
was more hospitable to life, Like it was actually sort
of more closer to what Earth looks like. Now, that's right.
We think based on evidence we see on the surface
of Mars now, you know, like the way the rocks
look and and the geological patterns, that Mars used to
be much more like Earth, almost covered with oceans like
(12:24):
there used to be huge amounts of liquid water on
the surface of Mars. Estimates vary from between thirty to
seventy of the surface of Mars used to be covered
in water like Us, just like Earth. Right, So Mars
would have been kind of a blue planet, not a
red planet, billions of years ago. And in addition, it
had a rich atmosphere much more than it does today.
(12:45):
And the atmosphere is key because an atmosphere is like
a blanket for a planet. I mean, you know that
emitting gases into our atmosphere is what's causing global warming. Well,
if you don't have any atmosphere at all, you can't
keep any heat near the surface. So you need some
sort of atmosphere just to trap the sunlight, you know,
to accumulate some heat and to prevent yourself from being
basically as cold as outer space. To Mars a long
(13:05):
time ago had a pretty robust atmosphere, which meant the
surface temperature was enough for liquid water, for example. So
that's a big difference. It just had this thin layer
of gas and that sort of protects acts like a shield,
like a bubble that lets you have liquid water on
the surface. Yeah, and it protects you against a lot
of stuff. Not only does it keep you warm, but
(13:25):
it prevents impacts from asteroids and meteors and stuff like that,
because when they hit the Earth, it's sort of like
an elfin hitting a water bed or something. It creates
a big splash in the atmosphere instead of getting all
the way down to the ground, right, and it probably
hurts too. Yeah. I think elephants like jumping on water
and what you're talking about. UM, But no, atmospheres are
very important, UM. For sustaining life, I mean life needs
(13:48):
to breathe, right, and also for keeping the temperature warm
enough and for protecting yourself against impact from from rocks
from space. So so marts you usually have these huge
oceans and sort of an atmosphere is like we do,
probably clouds, you know, beaches, um. So that's why we
think that maybe there could have been life. That's right,
as far as we know from a biological point of view, right,
(14:09):
what does it take to make life? Well, it takes
basic organic molecules, and those exist on Mars today, so
we're sure that they existed a long time ago. It
takes liquid water, right, it takes an energy source meaning
the sun um. And we don't really know what else
it takes. I mean, you can't have too many toxins,
you can't be blasted by radiation. Um. But we don't
(14:31):
really know. The deep question about in biology right now
is if you have all that stuff and you let
it sort of smooth around for millions of years or
billions of years, how often do you get life? You know,
is it one in a trillion, or is it every
other time? Or is it Planets that have that condition
eventually get microbial life we just don't know the answer.
(14:51):
It's like somebody makes the same ingredients we had here
in Earth, and the question is did little micro's pop
up in the middle of it? That's right, and you know,
my instinct is that it must have. And one piece
of evidence we have is that on Earth, it seems
like life started pretty soon after those conditions formed. You know,
once we had an atmosphere and the liquid water and
the temperature is about right, it didn't take very long
(15:12):
for life to start. So that suggests that it's not
like a one in a bazillion chance and millions of
years you suggests that, you know, it's likely to happen. Yeah,
think about all the molecules in an ocean, right, all
the organic molecules bumping against each other. You might think
it's so improbable for it to bump into each other
and form RNA and that something that would happen to
(15:33):
be self replicating and build from there. Yeah, it's improbable,
but you've got tend to the you know, huge number
of atoms bumping against each other for millions of years.
That's a lot of tries, right. If it's like you know,
monkeys on a typewriter banging away. Eventually one of them
is going to produce Hamlet. Yeah, it's a good picture
of of of a creator for the universe. Get a
(15:54):
bunch of monkeys banging molecules around. Oh look, i'mde Dna,
the creator. Sometimes it does seem like a like an
idiot monkey. Yeah, I agree. Welcome to blasphemy by Jorhand Daniel.
So that's kind of why we think that maybe there
could have been life because it looked just like the Earth.
It had the right conditions, but then all of that
(16:15):
went away at some point because the Mars we see
now it looks like a big, big old desert. Yeah,
that's why we think that Mars was a great laboratory
for answering this question. Right, If life existed on Mars
billions of years ago, when the conditions were great, that
tells you a lot about the chances for life to start.
If life didn't exist on Mars billions of years ago,
that tells you a lot about the chances for life
(16:37):
to start. Right. But as we alluded earlier in the podcast,
we don't actually know if life started on Mars or
life started on Earth. Right, it could have started in
either place. We should talk about that before we talk
about the great disaster of Mars. You mean, like, so
Mars used to look like Earth. Maybe life started there
and somehow made it over here exactly, And so you
(17:00):
might be thinking, Hold at a second, how could microbial
life like build a spaceship, launch it and come over
to Earth. That's ridiculous, right, Why is that ridiculous? Well,
I don't know. Bacteria don't seem to build technology, or
develop space ships or launched themselves into space very often.
I mean, not that we're aware of. Bacteria are secretly
exploring the universe. We don't little tiny rocket ships. Yeah,
(17:22):
but actually it happens, and it happens sort of accidentally.
And the way it happens is that you could have
like a piece of life, you know, a little bit
of bacteria on a rock, and that rock you get
knocked into space by the impact of an asteroid. So
you know, rock number one, come from space, blast onto
the plane, a huge explosion. Stuff flies everywhere. Some of
(17:42):
that stuff flies into outer space. Right. You can knock
a rock off the surface of a planet if you
hit it hard enough, and it would just go out
into space, float around the Solar System and land in
our planet. Yeah, and not all of them, of course,
would land on our planet. Most of them would just
float in space forever. But occasionally some of them will it.
And we know that this happens, like, for a fact,
(18:03):
we have rocks that we found on Earth that we
are sure came from Mars, so we know that this
is a thing. Wait, how do how do we know
they're from Mars? Do they have a little like a
made in Mars? It's the return postmark. Of course, it's
not so complicated. Um No, we can look at it,
the chemistry of it and the geology of it, and
they're just totally different from Earth rocks, and there's completely
(18:23):
consistent with what we think Mars rocks look like. And
you know, we've sent um robots to Mars. We've studied them,
so we know something about Martian geology and these rocks
just could not have formed on Earth and they're totally
consistent with rocks forming on Mars. So we have in
our labs rocks from Mars, right Like, we haven't been there,
but we already have pieces of it. So it's possible
(18:45):
that maybe you know, there was a little microbe who
went to sleep at night in his little rock or
her rock home. Something happened and the next day here
she woke up on Earth. Yeah that's right, probably the
next thousands of years. But you know, and microbes can
live along time and they can just go to sleep,
and a lot of them can survive crazy things. I mean,
there are microbes living on the outside of the International
(19:07):
Space Station right now. It's almost impossible to eradicate all
life from anything. I mean, you zap it with radiation,
you'll find a few microbes that are radiation hard. You
heat them up. You'll find some microbes that really like
it hot and dry them out. You'll find microbes that
can live in dry environments. It's crazy. So someone could
have survived the impact of an asteroid thrown into space,
(19:29):
surviving the cold and vacuum, survived the entry into Earth,
and then come out and be like, hey, this is
my new house. That's right. That thing has a great backstory.
Let me tell you there was a moment about what
is it now, twenty years ago when NASA thought they
actually had discovered evidence of life from a Martian rock,
right like a rock that came from Mars with evidence
(19:50):
of life in it. This was a pretty exciting moment.
People freaked out. Yeah, because NASA went and gave a
press release and said, we have this rock we're pretty
sure came from Mars, and when we cut it open,
we found these things in it that we think could
only be explained by life. They were these tiny little
shapes that looked like bacteria. They were much smaller than
Earth bacteria, but you know, you could imagine maybe this
(20:13):
is what life looks like on Mars. And so they
were pretty excited about it. But then what happened They
discovered that it was not actually microft tracks. Yeah. Well,
the scientists who suggested it, they still believed that it
was evidence for life, and to them it was the
most compelling story. But you know, in science, a pretty
big claim requires pretty big evidence, right, And so other
(20:34):
people dug into it and they came up with explanations
for how you could form those shapes using non organic
um processes, you know, just geological processes. Crystal formation could
give you this, and this kind of geology could give
you that, and so the rock could just naturally have
these formations. Yeah, they found plausible ways to make the
same thing without having to have microbial life. Yeah, which
(20:56):
is a bit of a bummer. It's a bummer that
we're not Martians. Well, it's a bum to not have
discovered life on Mars. I mean, that would be an
incredible moment, right to know that there was life on
another planet. But of course it still wouldn't answer the question.
Even if you found a rock with life from Mars
on it, you still wouldn't know did life come to
Earth from Mars, because then you've established that there's a
transport mechanism, or did it start on Earth and then
(21:19):
go to Mars and then come back, right, It wouldn't
answer that question. Yeah, but there's still also just the possibility.
I mean, they've proven that you can make these formations
some other ways, but that doesn't mean that necessarily that
those were not made by microbes. Right. It could be
that we're looking at evidence of life on Mars. We
just can't prove it, right, That's the problem is. And
before you're going to accept that, you really got to
(21:40):
have pretty solid evidence. You've gotta have something which is
unique to life, right, And so before you're going to
believe that there really is life or was life on Mars,
I think you gotta really see it. You gotta get there.
You gotta get some in your hands. You gotta life,
you know, play with it, see it move. You gotta
really be convinced. Chickens papers. Make sure it came from
birth certificate, you know, social Security number exactly. So we
(22:08):
think there might have been life on Mars a long, long
long time ago, right, And Mars used to look really different. Yeah,
it was more fertile, it was more sort of prone
to have life, that's right. Yeah it was. It was
a happy place to be, but not anymore. And the
thing that happened is that Mars lost its atmosphere. Something
happened that made it all sort of proof away. Yeah.
The atmosphere, the thing that would keep the surface warm
(22:31):
and have to have liquid water and you know, provide
the nutrients that life would need. That atmosphere got blown
away by the solar wind. See, on Earth, we have
an atmosphere, and our atmosphere is protected from the solar wind.
The solar wind is just like a huge flow of
radiation from the Sun. The thing that protects us from
the solar wind is our magnetic field, right. Mostly the
(22:52):
solar wind is charged particles being shot at us from
the Sun. But charged particles get bent in magnetic field,
and so our magnetic field mostly deflects them, and some
of them spiral down. And that's what you see in
the northern lights, right, is all these charged particles hitting
the atmosphere. It's like the Sun is shooting a giant
death ray at us. But we have some sort of
force field basically, right, we have like a special force
(23:12):
field that deflects it. Yeah. Literally, the Sun is the
death Star's fully operational and it's blasting us all the time.
And if we didn't have the magnetic field, then yeah,
we'd be in trouble because it would slowly eat away
at our atmosphere, would just strip it away, which is
blast walled our oxygen and air, and we'll be totally
(23:33):
exposed to those rates exactly, and then the temperature on
Earth would plummet and all of that stuff. And that's
what happened to Mars. We don't know why, just like
we don't have a great understanding of why Earth has
a magnetic field and why it flips. And you know,
we should do a podcast on that another time. But Mars,
we think had a magnetic field, which is why it
had an atmosphere, and then it lost it and it
might have been that it just cooled down and whatever
(23:55):
was happening inside Mars that you know, gyro magnetism that
created the magnetic field inside Mars just sort of stopped
and it lost its magnetic field, which means it lost
its its shield from the death star, which means it
lost its atmosphere dot dot dot, and then it got
blasted by the death ray from the Sun. And it
is what it is today, which is pretty barren and inhospitable, right, yeah,
(24:17):
And so it has an atmosphere today like you were saying,
but it's really thin, right. There's hardly any gas surrounding Mars,
so there's not enough to keep the surface warm. Right,
So if you go to Mars today, you wouldn't recognize
it from billions of years ago. You know, if if
life started on Mars and came to Earth and then
wanted to go home, it would be like, this is
not the Mars. I know, what have you done? Who
(24:38):
turned off the magnetic field? No, it's totally it's a
post apocalyptic healthscape I'm compared to what it used to
look like. But there could still be life there now, right,
That's right. We have not ruled out the possibility that
there could still be somehow life surviving on the surface, because,
as we said earlier, life finds a way to survive.
You know, once you have a planet that's just covered
(25:01):
in gazillions of microbes, they have a huge diversity, and
even in an enormous cataclysm, it's almost impossible to wipe
them out completely. Some of them will survive. And so
even though Mars lost its its magnetic field, it may
mean that there's no more life on the surface, right,
because it's no more liquid water on the surface, But
there could still be life on Mars. Right. What does
life need? It needs water, it needs nutrients, it needs um,
(25:24):
you know, not a whole lot of toxins. It needs
protection from radiation, some sort of a heat source, right,
A little bit of warmth, yeah, a little bit of warmth,
but you know, not too much, just enough to have
your water be liquid basically, and you know, a huge
caveat Somebody out there is probably thinking, hold on a second,
they're just talking about Earth like life, right, life like
it lived, like it exists on Earth. Whoever, you are
(25:46):
out there driving in your car thinking that we're totally crazy,
You're right, We're talking about Earth like life, because that's
the only life we know, and there's a possibility that
life could exist in completely different forms, you know, that
doesn't require liquid water and operates on geology called time
scales and frozen water. But you know, we're gonna have
to put that aside because it's so alien we can't
even really explore it or consider it or discover it. Right,
(26:08):
So for now, let's just think about earthlike life. Yeah, well,
let's talk about what we know about Mars and what
we can see today. But first let's take a quick break, okay, Daniel,
(26:30):
So what do we know about Mars today? Like, what
can we see that might lead us to believe there
are microbes or maybe little green men hiding hiding under
the surface that we can't see. Oh I wish they
were a little green men hiding onto the surface of Mars.
That would be amazing, right, what a discovery that would be. Well,
I know there's robots on the surface of Mars. There
are a few robots driving around Mars, but those are
(26:50):
Earth robots, Um there are I love these cartoons that
show like little green men hiding behind rocks to the
cameras from the rowers, right, like they're there, they're just
camera shy, yeah exactly. But you know, we have more
than just robots driving on the surface. We also have
satellites orbiting Mars and imaging surface and comparing the picture
today to yesterday. And so we're looking, Yeah, we're looking
(27:13):
if anything moved on the surface of Mars, and we
would notice, you know, it would not be hard to
spot some sort of activity. So we don't see any
movement or structures built by any civilizations or it just
looks like a big red rock. Yeah. What we see
our structures that look like you know, water flow canals
and geological formations, and so there's some activity on Mars,
(27:34):
but none of it seems to be like due to life. Absolutely.
So there's no large macroscopic life on Mars, which is
a bummer, you know, because that would have been awesome.
Um and you know, maybe Martian scientists could have tossed
the secrets of the universe, but that's not in the cards,
right that we can see, Right, that's kind of key.
On the surface, there aren't any that we can see.
(27:54):
But but it's hard to imagine though, like a technological
civilization living under the surface of Mars, and no presence
on the surface. I mean, imagine that was you. Right,
you have a civilization on the surface of Mars. It's thriving,
it's exciting. You know, life is good. You have you know,
fun plans on the weekend. All of a sudden, you
lose your magnetic field. The atmosphere starts stripping away, the
temperatures plummeting. You decided to go underground. Right, Still, you're
(28:16):
gonna want to have something on the surface to collect,
like solar power or something. Right, You're gonna leave some
evidence on the surface of the fact that we used
to be there. We see nothing, just natural rock. Yeah,
it's a fun concept for somebody's science fiction novel that
there could be today technological civilizations on the inside of Mars.
But I put it on a pretty low probability. Um,
(28:37):
but there is the possibility that microbial life could have
survived underground, so there could be an inside of the
rock instead of the dirt in Mars. There could be little,
little green microbes. Yeah. And the reason that we think
that the real possibility is that NASA has discovered water
on Mars. Liquid water, so not on the surface, because
(28:59):
on the surface is so cold that if you like
if you spat it would freeze in a crystal before
it hit the ground, right or evaporate right or evaporate
probably is probably more more realistic. But under the ground
it's warmer and it's protected from you know, all sorts
of radiation, etcetera, etcetera. And they found evidence of a lake,
huge lake of liquid water underground. But it's like a
(29:20):
mile underground. It's not like just under the surface. It's deep,
deep underground. How did they see it? How did they
know it's there? Yeah, they can see it by studying,
by using radar, I think. So they have ground penetrating
radar and all sorts of clever stuff to see what's
under the rock. So there could be like martian dolphins
swimming around in there in these caves. It'd be pretty dark.
(29:41):
I don't know how dolphins would survive and what they
would eat. I think much more likely is that there's
martian microbes right whatever. However, life started billions of years
ago could have survived on Mars. In turn, in these
lakes that are underground. Because there's liquid water, the ground
itself protects them from the radiation of the sun right
at the prays and so as long as they can
(30:02):
find some nutrients. And um, you know my wife, she's
a biochemist. She's always telling me that microbes can eat anything. Right,
there's nothing, no situation in which microbes can't find something
to extract energy from. Right. It's the opposite of children.
They won't eat anything. That's why I keep telling it.
We should have had microbes for kids and feed if
(30:25):
only I know, I know. Um. And there's also other
exciting information, like we actually have some clues that suggest
that there's life on Mars, not just the possibility. Oh
there's water, so there further could be there are other
things you can do look for life on Mars, which
is to look for biomarkers. Like if life exists, then
it has to have some sort of metabolism. Right, there's
(30:45):
like a process there. You know, it's eating something, it's
pooping something like their breath. Yeah there, yeah, exactly. And
so what we've done is we've looked at the atmosphere
of Mars and we've seen methane in the atmosphere. The
methane is not long lived, and so if you see
in the atmosphere, it means it was produced fairly recently.
But I mean it's not long lived like it it
goes away and it disappears. It breaks down. Yeah, it's
(31:08):
not stable. It breaks down the atmosphere under under sunlight
interaction with other things. Now, so we see these sort
of clouds methane appear and then they break down. So
something must be making this methane. Yeah, And there's some
explanations just you know that are that don't involve life,
like volcanic activity or whatever whatever. But the interesting thing
is that the methane produced on Mars varies with the seasons,
(31:30):
and so like you know, it's more in one season
and less in another season. Like you know, it's a
lot more in the summer and less in the winter.
And that suggests it's very suggestive of some sort of
biological process, right, as these things like sleep during the
winter and then wake up in the summer and eat
and fart a lot, because man, that's what methane is, right.
You'd be there and be like, m hmm, it's farting season.
(31:53):
Somehow in this podcast we always end up coming back
to farts. We should have called this for podcast farts
in science. Yeah, but our farts Mars called Mars. They're
called farshions. Um, so that's pretty tantalizing evidence, right, That
sells there's something going on that produces methane on a
seasonal scale. And it could just be volcanic activity that's
(32:14):
triggered by the Sun. There are some it could be
Mars itself, it's farting. It could be like the planet
is farting, like releasing we are smelling Mars's buttle exactly.
That could be the scenario. I think he went too farther.
I think they might have to edit that one out. Well.
I like this idea that you brought up the other day,
(32:36):
which is that, um, you know, we're sending these robots
to Mars, and you know, we try to clean in
them and clean them and disinfect them, but it could
be that we're accidentally sending life to Mars with these robots. Yeah,
almost certainly actually, because it's almost impossible to completely clean something.
Right you build on Earth, it's going to be covered
in Earth microups. I mean, they developed like special sprays
(32:58):
to disinfect this stuff, like super kill everything sprays, and
they sprayed on these satellites and then they discover, oh,
there's a kind of bug on these satellites that eats
that spread. It's like, I'm young, give me more, right,
So it's it's and you can shoot it with radiation.
You can do everything you like. It's almost impossible, which
means that when we send something to Mars, these rovers,
(33:20):
we are sending life to Mars. So is there life
on Mars? Well, almost certainly an earth microbe was sent there. Yes,
did it survive? Could it? Could it reproduce? Has it
like tainted Mars is going to colonize Mars and by
the time we get over there, it's gonna be covered
in Earth microbes. I don't think so, but you know
we It sort of muddles the question. And it's actually
zones on Mars where you're not allowed to send probes
(33:42):
because they're trying to keep it free from contamination. Wow.
So that's a huge twist. I mean, the answer to
the question is their life and Mars. You would think
it would be no, but the answer is yes, and
we put it there. I don't know that we can
say confidently if there are microbes on the surface of
those rovers, but I wouldn't bet against it. Yeah, I
wouldn't bet against it. So let me get to say
this is a total possibility life started on Mars a
(34:04):
long time ago, came to Earth through some freak asteroid accident,
evolved into us. We build robots and rocket chips, and
they put life back on Mars after there was this
apocalypse there. Yeah, and maybe that was their whole plan.
They saw this apocalypse coming and they're like, let's ride
a rock to Earth and then come back in a
billion years, you know, return to Mars. That's the title
(34:26):
of the sci fi novel we're writing. Yeah, And I
just think it's a fascinating question. And if we could
find microbs on Mars, I mean, say we send people
over there, or we get a sample of it, we
dig down a mile to even get a sample and
bring it back, then we could start to answer some
really interesting questions just by studying that life, right, Like,
is it um, RNA and DNA based the way our
(34:46):
life is? Is it similar? If it was totally different,
completely biochemically different, Wow, that would be fascinating because it
would mean there's different ways to build life. If it's
the same, that means either there's only one way to
build life and it happened in parallel and from places,
or it started in one place and went to the
other and man, there's so many amazing threads that you
could unravel if we just had a sample of that
(35:08):
lake from underground on on on Mars. Well, and the
answer in all these cases would be mind blowing. Right,
we're either super unique, we were either Martians, or there
is a totally different way to make life. Yeah, and
the facts are there right like right now, there could
be microbs wiggling around on Mars. And you know, it's
not that hard to get there. We have the technology,
(35:29):
we just lacked sort of the political will. You know,
it's amazing to meet these moments when you have the
technology and all you need to do is get the money,
and you could just buy the answers to deep secrets
about the universe. Right, it cost a few billion bucks
or whatever, but we could do it. If Congress and
the President decided this is important, let's do it, that
you could do it. So we have the opportunity we
(35:50):
could buy this knowledge. We just aren't all right, Well, tonight,
if you go out there and look at the night
s guy, you know, look up in an app of
where Mars is right now, and if you can look
at it at night, so you can go out there,
grab a Mars bars, eat it and look up at
that red planet and and smell it's farts. Yeah, or
turn around and send some farts to Mars and maybe
(36:13):
maybe that's the way they communicate farts is space. On
that note, if you still have a question after listening
to all these explanations, please drop us a line. We'd
(36:35):
love to hear from you. You can find us at Facebook, Twitter,
and Instagram at Daniel and Jorge That's one word, or
email us at Feedback at Daniel and Jorge dot com.
Hosts And Creators
Daniel Whiteson
Kelly Weinersmith
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