Phobos and Deimos: The Moons of Mars, Part 2

The god of war does not march into battle alone. His sons, embodying panic and terror ride beside him. The same can be said of the planet Mars and its two moons: Phobos and Deimos. In this episode of Stuff to Blow Your Mind, Robert and Joe discuss the Martian moons as well as a bit of mythology.

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Episode Transcript

Speaker 1 (00:00):
My Welcome to scoff to Blow Your Mind, the production
of My Heart Radio. Hey you welcome to Stuff to
Blow your Mind. My name is Robert Lamb and I'm
Joe McCormick, and we're back with part two of our
talk about the moons of Mars, Phobos and Demos. Now,

(00:23):
in the last episode, we talked a bit about the
mythology behind the moons of Mars, the companions and sons
of the war god Aries the Roman Mars, the god
of War, and we talked about how the names of
these came to be applied to the moons of Mars,
these two small objects that were discovered in the late
nineteenth century. We talked about that discovery story. We talked

(00:45):
about some of the basic properties of Phobos and Demos
and why there is some question about what their origin was.
We're going to get into more detail about that today.
And we ended up talking about a bizarre conspiracy theory
about out an interesting surface feature of Phobos that really
had nothing to it, but the surface feature known as

(01:06):
the Phobos monolith, is inherently very interesting. Yeah, and so
in this episode we're gonna we're gonna cover more interesting
stuff about Phobos. And demos uh stuff about the history
of its exploration. We'll get into another idea that conspiracy
theorists seem to really like concerning one of the two moons.
There'll be a dash of mythology here and there, but

(01:29):
it should be a fun ride, now, Robin, the last episode,
we were talking about how close the moon Phobos is
to Mars. It is the closest moon to its host
planet in the entire Solar System. Uh. It's so close.
I think it's a it's a matter of you know,
just like several thousand kilometers. It's a distance that is

(01:49):
a little bit longer than the driving distance between Miami
and Vancouver, as we talked about the last time. So
you know, if you if there were a road between them,
you could drive it in two or three days. And
that's incredibly close for a moon to UH to orbit
its host planet. But I found another point of comparison
that we didn't make in the last episode that I

(02:11):
thought was absolutely astounding, and it's that the moon Phobos
orbits so close to the surface of Mars that if
you are standing near the polar regions of Mars sometimes
you can't see the Moon even when it's on the
same side of the planet as you because it's blocked
by the horizon. It's orbiting down near the equator and

(02:34):
you can't see it over the curvature of Mars itself.
That that's unbelievable. Yeah, that is. That is pretty amazing.
And of course, as we discussed, it's getting closer to
Mars and will eventually, uh you know, millions and millions
of years in the future, will actually crash into Mars
or break up in orbit and become a new ring

(02:55):
around the planet. Yeah, they're gonna tussle. Yeah. But one
of the things we also alluded to in the last
episode is that these two moons, Phobos and Demos, have
extremely weird properties that really raised questions about where they
come from in the first place. And you can ask
this about moons all throughout the Solar System, like there
is some question about where the moon of Earth came from.

(03:20):
Those there's a there's a pretty strong leading theory that
is the giant impact hypothesis, the idea that early during
the formation of Earth, Earth was hit by a planetestimal
or you know, a Mars sized object roughly, and that
giant impact created a bunch of debris and eventually the
what was left over coalesced into the Earth and then

(03:41):
the Moon in orbit around the Earth. Indeed, uh, certain
properties of these moons as well discussed here, tend to
lend themselves more to one interpretation, and other properties if
you focus on those, lend towards another interpretation, which leads
to just a fair amount of you know, continued confusion,
but also inten fascination. Yeah, there's an article about this

(04:02):
that we were both reading that kind of sums up
some of the debate pretty nicely. It was published in
The New York Times by Robin George Andrews in July,
called Why the super weird Moons of Mars Fascinate Scientists,
and it briefly goes over some of the arguments either
way is now um. One of the things that points
out is that if you're just to look at the

(04:23):
what the moons appear to be made of, you know,
they're they're sort of physical characteristics in and of themselves.
They look a lot like captured asteroid's asteroids that at
some point would have been bumped off course and then
caught in the gravity well of Mars so that they
ended up just orbiting Mars. Permanently. Yeah, the the the

(04:46):
asteroid capture hypothesis, which which which is a popular one,
but it doesn't quite explain everything right now in its favor.
One of the main things that has going for it
is that the material that the Martian moons are made
of looks a lot like asteroid type material. Yeah, so
that they they look like asteroids. They seem to be

(05:07):
composed of the same material as asteroids. And yeah, they
would have just ended up too close to mars gravitational
pull and would have been simply orbitally dominated by the
planet Mars. The god of war says, you too, you
you shattered Rex. You are now my son's come with
me right into battle with me. It's like in the
cop movie when you commandeer the vehicle. You know, I'm

(05:30):
commandeering this vehicle, or James Bond gets into somebody's car
and drives off with it. Or I guess it would
be more like tying a car to you and making
it swing around you. I guess that an analogy isn't
that great, But yeah, it's it's saying you're coming with
me now, right. But the other interesting thing is that
they have that kind of throws this off, is they
have near equatorial orbits, and Is Andrews points out in

(05:51):
this article, this suggests that they coalesced from a disc
of debris that danced around a very young Mars. So
it basically it's just all too neat and tidy surely
to be an asteroid capture. So, in other words, like, okay,
if there, if it's asteroid capture, these are like wildcats.
But if they're wildcats, why are they behaving like orbital

(06:12):
house cats? So yeah, so that's that's part of the
big confusion here. Yeah, so you've got some creepy space
yukon golds that look like they're made of roughly asteroid stuff.
But the way they orbit Mars, it's a couple of
things actually, that their orbits are near equatorial, meaning that
they orbit basically, you know, not exactly, but pretty close

(06:33):
to around the equator line of Mars, you know, in
between its poles. And then the other part is that
their orbits are nearly perfectly circular. And this is just
not what you would expect to see with a captured asteroid.
If an asteroid came in that was originally orbiting the
Sun at a different speed and then it just got

(06:54):
stuck in the gravity well of Mars. What you would
probably expect to see is that it's orbit would be
more irregular, some more stretched out, right. You know, that's
often when something gets captured by an object and it
was originally on its own trajectory, it tends to have
a more stretched out oval type orbit. But then the
other thing is you would expect its orbit to be

(07:14):
tilted at a steeper angle rather than neatly orbiting pretty
close to its equatorial line. And then there's one more
factor that I think is worth considering. This is actually
cited in that article in The New York Times by
Robin George Andrews. And Andrews quotes a Japanese scientist named
Tomohiro Usui who points out that also Mars gravity is

(07:38):
pretty weak. I mean, you know, you can capture an asteroid,
but Tomohiro Sue points out that Mars has like a
tenth of Earth's mass, so it's kind of improbable that
it would be able to capture two asteroids that are
traveling by at orbital speeds, you know, speeds of orbiting
the Sun. So it just seems kind of unlikely as

(08:00):
an origin story for them and their orbits really don't
seem to match what you would expect from from asteroid capture. Now,
there is another hypothesis that would make some sense, which
is that what if the moons of Mars were formed
from a debris disc that was kicked up into orbit

(08:21):
around Mars after a colossal impact. So not exactly the
same as but but similar to one of the leading
ideas about where the Earth's moon comes from. There's a
giant impact on Mars at some point, and that shoots
all this stuff into space around Mars, which gradually coalesces
into a disc that's in orbit around Mars, and then

(08:43):
that disk gravitationally coalesces into solid objects, these two moons.
Now there's some reasons for doubting that as well. I mean,
one idea offered in this article is that Demos's orbit
is maybe a little too far out to be explained
that way, but that could possibly be overcome. One paper
I was looking at that supports the idea of a

(09:05):
giant impact as the original source of Phobos and Demos
was published in Nature Geoscience by Pascal Rosenblatt at All,
and it's called accretion of Phobos and Demos in an
extended debris disc stirred by transient moons um and so
that they write in their abstract that quote. Here we

(09:26):
use numerical simulations to suggest that Phobos and Demos accreted
from the outer portion of a debris disc formed after
a giant impact on Mars. In our simulations, larger moons
form from material in the denser inner disc and migrate
outwards due to gravitational interactions with the disc. The resulting

(09:46):
orbital resonances spread outwards and gathered dispersed outer disc debris,
facilitating accretion into two satellites of sizes similar to Phobos
and Demos. The larger inner moons fall back to Mars
after about five million years due to the title pull
of the planet, after which the two outer satellites evolve
into Phobos and Demos like orbits. The proposed scenario can

(10:10):
explain why Mars has two small satellites instead of one
large moon. Our model predicts that Phobos and Demos are
composed of a mixture of material from Mars and the
impact or so Again, this would be kind of similar
to the Earth's moon origin story. There's a giant impact
on Mars long long ago. It spits out all this

(10:30):
debris into orbit around Mars that forms into multiple moons
at different orbital distances, and then interactions between those eventually
cause inner moons to be destroyed spiraling into Mars as
Phobos will one day do, and then uh, and then
these other objects to coalesce into the current orbits that

(10:51):
we see for Phobos and Demos. So that's one plausible
possibility they've put together. Yeah, and this satisfies some of
the mysteries that we discussed earlier. How can it be uh,
have the qualities of an asteroid capture, but also have
the qualities of of something that formed out of a
desk around Mars. Now we've mentioned that Phobos as its
spirals into Mars will probably break apart. I mean, we

(11:13):
mentioned a couple options. It could just crash into Mars.
More of the sources that I was reading seemed to
suggest that the more likely option is that as it
spirals into Mars, it will be sort of ripped apart
by tidal forces and it will break up and become
rings in orbit around Mars. But really interesting question that
I came across in another study in Nature Geoscience, this

(11:35):
one published in This is the question of what if
this future scenario where Phobos breaks up in orbit around
Mars and becomes rings. What if that has already happened.
Very interesting origin hypothesis for for these two moons. So
this is by Andrew J. Hessel Brock and David A. Minton. Again,

(11:56):
that's nature geoscience in seen called an ongoing satellite ring
cycle of Mars and the origins of Phobos and Demos.
Now this uh. This explanation has a similar beginning as
the last one, but some of the details are different.
Again to read from their abstract, the Martian moons Phobos
and Demos may have accreated from a ring of impact debris,

(12:17):
but explaining their origin from a single giant impact has
proven difficult. One clue may lie in the orbit of
Phobos that is slowly decaying as the satellite undergoes tidal
interactions with Mars. In about seventy million years, Phobos is
predicted to reach the location of tidal breakup and break
apart to form a new ring around the planet. Here

(12:39):
we use numerical simulations to suggest that the resulting ring
will viscously spread to eventually deposit about eight percent of
debris onto Mars. The remaining twenty of debris will accrete
into a new generation of satellites. Furthermore, we propose that
this process has occurred repeatedly throughout martian His story. In

(13:00):
our simulations, beginning with a large satellite formed after giant
impact with early Mars, we find that between three and
seven ring satellite cycles over the past four point three
billion years can explain Phobos and Demos as they are
observed today. Such a scenario implies the deposition of significant
ring material onto Mars during each cycle. We hypothesize that

(13:24):
some anomalous sedimentary deposits observed on Mars maybe linked to
these periodic episodes of ring deposition. So Phobos or the
ancestor of Phobos could have been once much larger, maybe
twenty times more massive. But then there's this pattern that
repeats over time, almost like you know, the mythological cycle
of history, where there's orbital decay. It's it's going closer

(13:48):
and closer down into Mars. It shatters from tidal forces,
it's you know, turned, it splits apart into a million pieces,
forms a ring around Mars. The pieces of the ring
then coalesce into a move and then repeat with the
Moon getting smaller every cycle. I love this because if
you if you take it and then apply it to
the mythological model that we've been discussing here, you have Mars,

(14:11):
who is you know, actually more the the you know,
we can would think more of the Greek war god
aries representing the worst of war, just the the bloodshed
and the screams. Just this awful deity, the god of
the screams of the dying. Yeah, yeah, the god of
the screams of the dying. And so it makes sense
that his two loyal sons who are destined to rebel
against him have always rebelled against him. Like there's a

(14:33):
cycle of them rebelling against the Almighty Father here, being destroyed,
breaking up, but then he reforms them. You know, it's
like they're resurrected to continue to serve them as these
kind of misshapen wraiths. Oh man, yeah, I love that.
Another way to think about it is if you're talking
about a god of war, I mean, this is the
process of attrition, right, slowly wearing down your enemy's forces

(14:58):
over time. Yeah, yeah, they coming back, but each time
weaker and weaker. Now, like many things in space science,
this is one of these great fascinating open questions that
really could uh, we could really have a better chance
of solving if we were to have more physical data
to work with. And so this is one of the
many reasons that there have been all these proposed missions

(15:19):
to the moons of Mars, and including that, there's a
there's an upcoming mission that we'll talk about in a
bit from the Japanese Space Agency from Jackson that is
planning to go to the moons of Mars in I
think it's supposed to launch in four and hopefully arrive
in But there we could learn more about the composition
of these moons, which could maybe tell us more about

(15:40):
their history. But to come back to that New York
Times article we were talking about, Uh, there's a part
of it which says, quote, although made of ancient matter,
the Phobos we see today may have been assembled just
two hundred million years ago. If it were confirmed that
Phobos is a haphazardly clumped together mass, it would be
a revelation suggesting planets with rings are the norm for

(16:02):
our Solar system. And I had to think about that
for a second, and then I realized, like, oh, yeah, okay,
so if it's normal for Mars to have a ring,
and we just happened to be observing it during one
of its you know, interring periods, one of its ringless periods.
That would mean the majority of planets in our Solar
system of rings. Jupiter as rings, Saturn has huge rings,

(16:24):
uh Uranus has rings. So you'd realize that rings are
the standard and a planet without rings is actually weirder. Yeah,
I guess it's kind of like thinking about cities, right. UM.
Imagine you know, most cities have some sort of sprawling suburbs,
but maybe you have a city that doesn't really have
suburbs but just has like a a centralized satellite uh

(16:44):
town outside of it, maybe to such satellite towns. Um.
But if that was the main thing you saw, you
might think, oh, this is just how it works, This
is how cities are come together. Though, one thing I
should point out from that article that they quote again
the Japanese researcher tell my hero Sui who uh says
that you know, this that we were just talking about
could possibly be true of Phobos, but at the same time,

(17:06):
not for demos. It's possible that they you know, that
they have these different origins that they're not exactly the
same thing. So Demos could be much older than Phobos. Potentially,
uh Suey says that Demos could be three point five
billion years old, whereas it's it's possible that Phobos is
much much younger, just like two million years old. But
again it's one of those things that it'll be hard

(17:28):
to know for sure until we send something there and
maybe even bring part of it back. Than I'm ready
to get weird. Do you want to talk about some
weird historical hypotheses about Phobos? Yeah, concerning the idea of

(17:48):
a hollow Phobos. Now, one thing I want to stress
here is again we'd love to have physical evidence, physical
material to look at regarding Phobos and Demos, but we
don't yet. Hopefully in the future, but we don't have
it now. What we have are, in addition to to
various other readings, we have visual images taken via fly

(18:09):
bys and and and Mars missions. But there was a
time where we didn't have those additional um images. So
I want to go back to the late nineteen fifties
and ultimately to the decades preceding that, and the work
of Russian astrophysicist uh Yosef Shaklovsky, who hypothesized that phobos
might be hollow and even more to the point, might

(18:32):
be an artificial structure. Oh yeah, Now, Yoso Shaklovsky was
born nineteen sixteen died five. He was a Soviet astronomer
and astrophysicist. And we've actually mentioned him on the show
before because he co wrote and he had for the
main credited author on intelligent Life in the Universe with

(18:56):
Carl Sagan in nineteen sixty six. I believe we discussed
it in our Look at Ancient Astronaut hypothesis, which you know,
the basics of which they went into in this book.
And in a in a way this this book was
was kind of pivotal to the whole Ancient Aliens movement,
even though I have to stress the Chaklovsky and say

(19:16):
Agan they discussed it rather uh, you know, very in
a very grounded nature, very scientifically. Um. And it's other
authors who really have would run wild with it and
um and just you know, go off the speculative deep
end with it. You know, there's something I notice in
the in the responsible science journalism of today that is

(19:38):
a kind of automatic, reactive opposition to the subject of
like aliens or evidence for aliens, and and I get
it right, because if you're covering space, if you're covering astronomy,
if you're covering space missions, you know, in anything having
to do with space, one of the things you're going
to be dealing with most often is people your respond

(20:00):
sibly taking some piece of evidence that in no way
really indicates evidence of alien life and saying it's aliens,
and that they're just going to be doing that over
and over again, and then you just end up having
to spend your career writing article after article of like, no,
this rock on Mars is not an alien. There's no
reason you have to conclude that. You know, natural wind

(20:22):
erosion can cause features that look strange like this, here's how,
And then you can end up explaining interesting things about
natural science about like how wind erosion can cause something
to look sculpted or designed in a certain way, or
you you know, you end up saying like, no, we
we don't have any reason to conclude yet that the
signal coming from this star, even though it's like repeating,
is an alien. And then you can explain stuff about

(20:44):
pulsars and how they work and what we know about
them and that's all good stuff. But I think because
there is such a tendency for for hoax hype people
and for the public generally to get over excited about
something that's mysterious and say, therefore it's aliens, you can
start getting opposed to even playing with the idea of aliens, right.

(21:05):
It starts to become like subject matter that's almost like
inherently revolting to you. Does that make any sense? And
I'm very much like I I very much respect all
the skeptical work, you know, and we do that too,
Like we we end up having to say, like, no,
there's no reason to conclude this is aliens. Nothing we
have ever discovered in space is definitely aliens. There's no

(21:26):
reason to think that there's never even really been a
strong piece of evidence for aliens that we've come across. Uh.
I think that there's no reason at all to go
from there to say, so therefore, like, don't play around
with the idea of aliens, Like what would what would
be evidence if we were defined it? Yeah, I mean
it's kind of like with the Uamua, you know. I

(21:46):
think there's gonna be There're gonna be people out there
who are just always going to be convinced that was
a spaceship. It wasn't. It was not a spaceship, right,
But you know, certainly the spaceship interpretation is one that
is you know, way weird, way easier to fathom because
it's so uh, it's so based in science fiction. You know,
you don't need a breakdown a discussion of like why

(22:07):
this thing was ejected from from some distant uh interstellar locale,
you know. Um, And yeah, it's just more exciting. But
to a certain extent, any coverage of Mumu will always
involve having to to really remind everybody that there is
there's there's no strong evidence that it was a spaceship,
that it was not a spaceship, but let's explore these

(22:29):
these also these other fascinating ideas and hypotheses concerning its
origin and its nature. Sure, so, I mean I feel
very attracted to kind of the the Carl Sagan outlook,
never saying like, oh, yeah, it's aliens when you see
something you don't understand, but also feeling fully free to
speculate about the idea of aliens because it's an interesting subject.

(22:49):
I mean, it's fun to think about and and consider
what the real scientific implications of the existence of aliens
would be even though you're always going to try to
remain skeptical and grounded and not interpret every new piece
of information about the universe that you can't currently explain
as an artifact of an alien civilization, right right. And
then the second was great with this. You know, he

(23:11):
was always open to exploring those big questions and those
those those um, you know, the more radical questions, but
doing so in a balanced way. We're saying, well, okay,
let's let's talk about it. Yes, it could you know,
aliens certainly could exist, They could have visited the Earth.
There could be evidence of it in the historical record.
But what would that look like, what specifically would we

(23:34):
be looking for? Um? But that is a far healthier
approach in my opinion. Yeah, And for me, I think
it's just like important to just always emphasize the lines between,
you know, factual reporting and intellectual play. Yes. Now, interestingly enough,
in in this book and in question here Sholowsky and
say again they described phobos and demos as quote, the

(23:56):
chariot horses of the god of war. Um. And I'm
I'm unclear on where that comes from exactly than being
horses as opposed to or in addition to being the
sons of Arias. But I think it still checks out,
you know, whether their war horses or or of sons,
that they're kind of treated like war horses. Yeah, I
mean Areas could have had some horse sons that would

(24:19):
make sense. Yeah, yeah, I think so. Another bit that
they note in the book, and I do want to
continue to drive on this is the nineteen sixty six
book um quote. Thus, if we neglect the artificial satellites
of Earth, Phobos is the only known moon in the
Solar System with a period of revolution about its planet,
which is less than the period of rotation of the

(24:39):
planet itself. Yeah. So it takes Earth's moon roughly a
month to orbit the Earth, right, Uh, it takes less
than a day for Phobos. Two less than a Martian
day for Phobos to orbit Mars. I think it orbits
like three points something times every Martian day, And by
very nature, a Martian day is one rotation, so it's

(25:00):
kind of it's easy to miss that that that point.
So I like the way that it really drove that
home here. So if you're you're clocking in at work
for your your Martian work day. Oh there goes Phobos,
and then maybe you could look at Phobos again to
know when it's time to go home. Yeah. Now, if
it wasn't already obvious from the association with Sagan, I
want to be clear that Shaklovsky was no quack. In fact,

(25:22):
there's a crater on Phobos named for him, Shaklovsky Crater.
But he was. He was understandably intrigued and confused by
the Martian moons for decades, for the reasons that we've
already stated. Um. Sagan in nineteen sixty six described Shakowsky's
ideas concerning uh, the idea of a hollow Phobos as
quote uh the only serious extant arguments supporting intelligent life

(25:45):
on Mars now to now. Certainly, additional information eventually discredited
this notion, um. But it's interesting to look at how
he got there. And the book was Sagan contains a
fair amount of of math and technical information. It's not
it's not, you know, certainly not a technical paper, but
it's certainly not the wide audience work of science communication

(26:06):
that we often associate with with Sagan. Solo books and
articles to come, but they they break down this idea
in a great deal again based on data from nineteen
sixty six and before so Schklovsky's idea of a hollow
Phobos and then eventually tying that to speculation about alien life.
This is something that is no longer an option given

(26:28):
what we know about Phobos today. But we're exploring this
as a historical curiosity of a hypothesis. Yes, yes, so, Uh,
here's the here's one of the main points here. I'm
gonna read from from the article and uh, and I
should mention as well that in these some of these quotes, um,
they'll be using I, and I think we're very much
that I is referring to shakovski quote. But how can

(26:52):
a natural satellite have such a low density. The material
of which it is made must have a certain amount
of rigidity, so that cohe if forces will be stronger
than the gravitational tide forces of Mars, which will tend
to disrupt the satellite. Such rigidity would ordinarily exclude densities
below about zero point one Graham's per centimeter to the

(27:12):
negative third power. Thus, only one possibility remains. Could Phobos
be indeed rigid on the outside but hollow on the inside.
A natural satellite cannot be a hollow object. Therefore, we
are led to the possibility that Phobos and possibly Demos
as well, maybe artificial satellites of Mars. And if so,

(27:34):
quote they would be artificial satellites on a scale surpassing
the fondest dreams of contemporary rocket engineers. Now again, this
hypothesis is no longer really viable given the evidence that
we have available to us today. But what what a
wild and wonderful idea? Yeah and uh and Chicolo assually
continues to to to back this up and make some

(27:56):
arguments around it. I'm gonna roll through some of them here.
First of all, he says, this idea might seem fantastic
at first glance, but it demands serious consideration because a
technologically advanced civilization would certainly be capable of manufacturing and
launching such an advanced satellite. And if Mars did not
have any natural moons, the establishment of artificial moons would

(28:20):
be a greatly important endeavor to any native civilization, or presumably,
and this is just my reading of it, any civilization
that took a strong interest in the planet. Further More,
Shaklovsky says it it would be much easier for a
Martian presence to launch a satellite than for you know,
earthlings to launch a satellite. Due to the reduced Martian gravity,

(28:42):
less work is required to get something into orbit. And
also quote, conceivably, the capture and hollowing of a small
asteroid might be technically more feasible than the construction in
orbit of an artificial satellite with material brought from the surface.
In our future, uh he says, we too might construct
such artificial satellites, and if we pass on into extinction, well,

(29:05):
those satellites might remain. And if so quote, we cannot
reasonably assess these possibilities. But it does seem conceivable that
the lifetime of our artificial satellites may exceed the lifetime
of our civilization. These satellites would then remain as unique
and striking monuments to a vanished species which had once
flourished on the planet Earth. So hypothetically, if Mars had

(29:29):
once harbored advanced life forms and they developed an advance
enough civilization, they might have established such artificial satellites, perhaps
some hundreds of millions of years ago. So again, to
be very clear, it is not currently the case that
there is evidence to the points strongly to an artificial
origin for these moons, though of course all the interesting
mysteries about their natural origins remain. But to add to

(29:53):
the the beauty of this idea, uh, there's another fact
about Phobos I wanted to add, which is that it
is thought to have a a very thick layer of
powdery regulars all around the outside of it, So it has, uh,
it's it's often thought to be very deep. I've read
estimates that it's like a hundred meters deep, So it's like,

(30:14):
you know, over three hundred feet deep of this powdery,
dusty material, this regulars on the outside of it, which
which gives the possibility that if in this alternate universe
scenario where these moons were artificial creations of ancient technology,
you could literally maybe uncover surface features of them indicating

(30:35):
artificial origin by dusting, by moving the dust away, you know,
like like the movie scene where you wipe the sand
off of a sign and see the writing on it,
dust off of the the artifact and determine what it is,
except I guess would be a hundred meters of dust,
So that'd be that's that's mega dust. Now, you know,

(30:56):
we were talking about the difference between you know, comeing
up with a controversial hypothesis versus just running wild with
radical ideas. And it seems it seems like Shaklovsky was
mindful of this as well, because he points out that
that there are stronger and less favorable versions of this

(31:16):
kind of line of thinking. He points out that Soviet
researcher and someone who's who would later come to be
known as the father of Russian ufo ology, Felix Ziegel,
had an even more extreme notion. Uh, perhaps phobos and demos.
Ziegel argued, perhaps they weren't discovered by the astronomer Herschel
during the favorable Martian opposition. That means, you know, the

(31:39):
closeness of Mars to Earth and therefore it's increased um
visibility via telescope. Uh, perhaps Herschel didn't discover these moons
in eighteen sixty two and instead they were discovered by
this by a smaller telescope in eighteen seventy seven, because
they were not there in a teen sixty two. Rather,

(32:01):
they were launched after eighteen sixty two by an existing
Mars civilization, and therefore, uh, we're there to be discovered
in eighteen seventy seven seems implausible, yes, And Silklowski dismisses
this notion for several reasons, in part because the naval
telescope that was actually used to discover the moons, while smaller,

(32:24):
was still superior to Herschels. And he contends that if yeah,
the Shilklaski is very into this idea that the moons
could be artificial, but he's like, the only way this
works is if they were also ancient. There's no way
that these were just launched in the past few years. Uh.
And part of that also comes down to, you know,
we've discussed this in terms before, like one of the

(32:45):
rules of of of observing the cosmos is to realize
that or to work from the vantage point that we
have we do not have a privileged place in the universe, uh,
in space or in time. So the idea that we
just happened to be looking at Mars one day and
there were no moons, and then we're looking at it

(33:06):
years later and there are moons because they were launched
in the interim, that's just it's just too perfect. It's
it's just too unlikely. And this is actually one of
the reasons that Klowski says that that he thinks that,
you know, another reason that that Phobos could have potentially
been some sort of artificial creation. He points out that
it's eventual crash into Mars means that we are in

(33:28):
the unlikely position of viewing the moon during its final days. Um.
I mean, you can argue that we're not really talking
about days, We're talking about millions and millions of years. Uh.
It's just astronomically speaking, their days. Uh. And he argued
that it was quote an unlikely but not impossible coincidence. Now,
all of this being said, Chicosi also insisted that if

(33:50):
ancient Mars was truly this advanced, advanced enough to create
huge artificial satellites and either construct them in orbit, make
them out of asteroids, or launched them into orbit around Mars,
then we will We're bound to eventually discover evidence of
this civilization, not only you know, via the satellites of Mars,

(34:10):
but also Mars itself during the future exploration of the
red planet and as far as the moons themselves go,
he said, well, eventually we're going to conduct fly bys
and the and the images that we gain from these
this will shed light on them. Will they have special
shapes for example, And of course the answer would prove
to be yes, but also sort of no as well,

(34:33):
because as we've discussed, like, Phobos does have an unusual shape,
but is it is it a special shape? Is it?
Is it a shape that that screams um artificial construction? Um?
I think pretty much everybody would argue no. I can't
wait to read the articles about how no, actually the
shape of a Yukon gold potato is the perfect shape

(34:53):
for for an orbital launch platform or whatever. This thing
was supposed to be a space elevator, and I think
that's what some of it's aliens people are saying today, that, uh,
that that Phobos was an ancient Martian space elevator. Once again,
there is no strong evidence of this, is I mean,
it's find a play around, have fun speculating about that.
But you know, understand the difference between playing with an

(35:16):
idea and saying like that there's actually strong evidence for it.
There is not, right, Yeah, because because certainly Sholkovsky ultimately
contended that while his own hypothesis was scientifically sound at
the time, though there were some uh, there were some
arguments and some and certainly some opposition to his ideas
and people saying, well, I don't think we need to
go that far and trying to explain Phobos. Um. Sholkovsky

(35:40):
still acknowledged that future explorations would put his hypothesis to
the test, and that it very well could prove incorrect.
And if it proved incorrect, though, then it would have
still served the purpose of forcing people to think about
the sorts of advanced work that aliens cultures would have
constructed or could have constructed, and what would remain of them,

(36:03):
and therefore what we could potentially look for, uh, in
terms of of evidence of extraterrestrial intelligence and extraterrestrial life. Yeah.
And of course, one of the signs of a good
hypothesis is that it makes specific predictions that can be
tested in the future, right and uh, you know, And
again this means nothing to people who want to run

(36:23):
wild with the idea that Phobos is hollow and as
an ancient space elevator. I was looking around briefly and
I ran across one of these pages and they referred
to shak Lasky here, but they referred to his quote
unquote findings, uh as if he had proven uh, you know,
without any doubt that Phobos was a hollow artificial satellite,

(36:45):
and that just that is absolutely not the case, exactly right.
But coming back to the original thing leading people off
in this direction, while it's not indication of an artificial origin,
there is something interesting about the composition of these moons.
I mean, so like, if you look at Phobos, it
has weird density. It seems very low density for a

(37:08):
moon or an object of this type. So that leads
to other questions like what would be the cause of
this low density in the moon if it's not you know,
a hollow alien spaceship or something, which again it's not,
and what would be the implications of that low density?
And this leads us into our next section because we
have some current hypotheses that hold that the density problem

(37:28):
is likely solved by in some cases large spaces within
Phobos that are not areas that were hollowed out by
an ancient civilization, but could be due to just the
the the structural qualities of Phobos itself, the way it
came together as essentially a big old heap of space junk, right,
And this ties into something else I was reading actually,

(37:51):
so I was looking at a NASA feature from by
Elizabeth Zubritzky called Mars Moon, Phobos is slowly falling up heart. So,
as we mentioned already, Phobos is doomed to spiral into
Mars and either crash into it or break up and
become rings. This will probably not happen for tens of

(38:11):
millions more years. Actually, the estimates I've seen for this
or sort of all over the place. Some say this
will happen in thirty to fifty million years, some say
fifty million years, some say a hundred million years. Um.
So I don't think that there's an actual really tight,
you know limit on that pin down, but it seems somewhere,
you know, thirty to a hundred million years from now

(38:33):
it is expected to break apart into a ring or
crash into Mars. Probably more likely break apart into a ring,
which is still pretty close in astronomical time. Uh yeah,
well again, we're only looking at the end days astronomically.
From a human standpoint, this is so far in the
future that it's it's it's hard to imagine that these
will truly be humans that observe it, if humans are

(38:54):
around to observe it at all. Right, but you remember
last time, how we talked about we were looking at
surface features of Phobos, and one of the things we
talked about where the cat scratches, you know, these long
grooves along the surface of the Moon. And so what
explains those grooves. Well, in this article it quotes a

(39:14):
researcher named Terry Herford of NASA Goddard who says, we
think that Phobos has already started to fail, and the
first sign of this failure is the production of these grooves.
And so Zubritsky writes that quote, phobos grooves were long
thought to be fractures caused by the impact that formed

(39:35):
the Stickney Crater. Remember the Stickney Crater is that huge
crater on one face side of Phobos that was named
after Angeline Stickney, who worked on observing Mars during the
eighteen seventies along with her husband ASoft Hall. But coming
back to this article, so the idea was that you
had this crater caused by a collision with Phobos long ago.

(39:56):
Quote that collision was so powerful it came close to
shatter Phobos. However, scientists eventually determined that the grooves don't
radiate outward from the crater itself, but from a focal
point nearby. More recently, researchers have proposed that the grooves
may instead be produced by many smaller impacts of material

(40:17):
ejected from Mars, But new modeling by Herford and colleagues
supports the view that the grooves are more like stretch
marks that occur when Phobos gets deformed by tidal forces.
Now these would be tidal forces caused by its close
orbit around Mars. Now remember, tidal forces occur when there

(40:37):
is a significant difference in gravitational forces felt by different
parts of the same object. So when something is orbiting
close to a huge object, it will often experience tidal forces.
A very extreme case of tidal forces would be the
idea of spaghettification, the much celebrated way of dying as
you go into a black hole. As the if you're

(40:58):
falling feet first, the the gradient of gravitational uh forces
that you feel as you fall into the black hole
are so extreme that the difference between the forces on
your feet and the forces on your head would sort
of stretch you out like a noodle. But in more
mundane scenarios, tidal forces are also responsible for things like
the actual tides right you know, as as Earth and

(41:21):
the Moon orbit each other. They exert gravitational influences that
are not evenly distributed on the entire sphere of the
other body, but they pull like specifically at the at
the facing equatorial region of the other body, right, And
so this results in tides in the water on Earth.
But also you can see that the spheres of Earth

(41:42):
and the Moon are also kind of they kind of
bulge out at the middle around the regions where they're
they're most pulled on by the other body. Now, in
the case of Phobos, it was once thought that tidal
forces should not be strong enough to be stretching apart
a moon like this, But that was when Phobos was
assumed to be solid all the way through at the

(42:04):
time of this writing, And I wonder how this idea
has matured since then. It's possible that there have been
some arguments against it in the meantime, but at least
at this time. In these findings from from NASA, Goddard
where that the interior of Phobos is more likely to
be this kind of loose collection of rubble is sometimes
referred to as a rubble pile, and that it's all

(42:27):
just sort of barely stuck together and then quote surrounded
by a layer of powdery regularly about three hundred and
thirty feet or a hundred meters thick I mentioned that earlier, right,
So on this model, you've got this blanket of dusty
powdery regular sort of uh, sort of like acting like
the bindle sack for a bunch of rocks that are

(42:49):
just barely loosely held together by gravity. So if this
model is correct, then there's actually not all that much
holding the core of Phobos together. It's just a bunch
of junk kind of loosely stuck together by gravity rather
than a single massive, rocky core, and title forces will
have a much easier time ripping it apart than it

(43:11):
would ripping apart something that was more solid. And again,
mythologically speaking, I think this sounds perfect the idea of
the war god's son being this, this fast and fearful
uh creature on the battlefield, but ultimately he's just this
this wreck, this just partially hollow, falling apart, doomed, you know,

(43:33):
wraith of a warrior. Than now, we've been looking a
lot at Phobos, and to be fair, I mean I
think there's a reason for that, Like a lot of
the real interest and research and big questions have been
focused on Phobos, but Demos is interesting too, so maybe

(43:53):
we should take a quick look at Demos in particular. Yeah,
Demos is the smaller of the twins. It's not and
by seven by six point eight miles in size or
fifteen by twelve by eleven kilometers. It goes around Mars
every thirty hours. It doesn't have grooves and ridges like Phobos,
but it has plenty of craters. Uh. And while you

(44:14):
know normal craters on on other uh, you know, bodies
are surrounded by ejective from the impact. You know, the
stuff that gets launched up when that impact takes place.
Damos is gravity is low enough that impact ejecta achieves
escape velocity. Uh. So it doesn't fall just immediately fall
back down. Instead, the debris remains in a ring around Damos,

(44:37):
it seems, and then it's slowly redeposited on its surface. Now,
we talked in the last episode about how even though
Phobos is extremely small for a moon, it's so close
to Mars that when you look at it from the surface,
it looks pretty substantial in size. It's like not quite
as big as the Moon looks from Earth. But like
a substantial fraction of it, you can see it as

(45:00):
a disk and not just a dot. The same is
not true for Demos. Right from the surface of Mars,
Damos would appear star like in the sky. That's how
small it would be. It would just look like a star. Uh,
you know, it would you know, they would stand out
a little bit, but it would essentially just look like
a star. And that's that's interesting because it runs counter

(45:20):
intuitive to what we think of when we think of
a moon. Now, when it comes to named craters on Demos,
there are only two, Swift and Voltaire, chosen for obvious
reasons because, as we explored in our first episode, the
works of Swift and Voltaire were early works that alluded
to Mars having two moons in advance of those two

(45:42):
moons actually being discovered. But I was reading in uh
in Broca's Brain, the book by Carl sagan Um. He
has a whole section where he goes into like the
naming of Mars. He lists a bunch of the different
gods in addition to the gods that we uh that
we discussed, that have been associated in different cultures with
the planet Mars ours Uh and he shares that in
addition to Swift and Voltaire, he wanted to name a

(46:05):
third crater of Demos after Um, after Renee uh Margretti,
a Belgian surrealist whose paintings featured large rocks and suspended
in the sky, or at least two of his paintings
depicted large rocks suspended in the sky, and they reminded
Sagan of the Martian moons. Quote. The suggestion was, however,

(46:28):
voted down as frivolous. But if you look up some
of these of these paintings by the artists, like they
they are really cool, they don't you know, they don't
look exactly like uh Phobos and Demos, but they are
the surrealist images of large rock craggy boulders suspended in
the sky over the ocean or a landscape. In one
case there's a castle on top of one of these boulders.

(46:50):
In another case you see uh crescent moon in the
sky above. It clearly an inspiration for Zardas now Um obviously,
you know, given it's a very small moon Uh, and
it is also further away from Mars than Phobos. And
while Phobos, as we've discussed several times already, is faded

(47:10):
to one day crash into the red planet or break
up against its power. Damos is drifting further away and
will one day escape Mars entirely. Uh though from a
mythological standpoint, this I like. I like this too, because
the this doomed, insane godling who will one day earnest freedom,
he'll one day escape the awful war god uh that

(47:34):
that he has served. But he's just gonna wander out
into the waist of the Solar System, perhaps crash into
lesser deities or mortals and die by their hands instead,
or just wander aimlessly. Uh So that's it's kind of
perfect in its own way. Now, we've talked about the
idea of missions to the moons of Mars in order
to study them and perhaps even return a sample from

(47:54):
them that would allow us to better understand where they
come from and what they are. There's actually another one
of the scheduled It's Japan's Martian Moons Exploration or the
MMX mission of Jackson, the Japanese Space Agency, which is
currently scheduled to launch in and perform an orbital insertion
around Mars in and so it would travel to survey

(48:18):
both of the planet's moons. And then the idea is
that it will land on Phobos and collect a sample
from Phobos to bring back to Earth for study. And
major scientific objectives of this mission would include determining the
origin of Phobos and Demos, so possibly answering these big
questions that we've been talking about all this research on today.

(48:40):
So are they actually captured asteroids that just happened to
have these very tidy orbits? Are they the result of
a giant impact with Mars long ago and so forth?
And uh? And also we should be able to study
the history of Mars itself by looking at these moons.
But as far as space exploration goes, there's another interesting
thing about the moon Phobos, which is that it has

(49:02):
often been proposed as a potentially useful base of operations
for space missions. Yeah, for the same reason Shilowsky outlined,
it would be advantageous to have a moon like Phobos
above your Mars. If Phobos did not exist, it would
be necessary to invent it. And since it does exist,
it would make a handy base. Yeah. And so one

(49:24):
of the things is that it has been proposed as
a remote control base of operations for surface robots on Mars.
So this would eliminate the problem that when we want
to control rovers and exploration vehicles on the surface of Mars,
there is a large time delay between Earth and Mars
where we have to wait after we transmit a command

(49:45):
signal for that signal to reach the robot and it
performs the operation, and then we have to wait to
receive feedback, and this can be a while while you're
just sitting there, you know, waiting for your your signal,
your remote control signal to reach the rover, and so
that this can cause a lot of slow down and
difficulty in these kind of missions. If you could get
your humans onto the surface of Phobos, they could essentially

(50:10):
control things operating on the surface of Mars remotely in
real time. And it would be better trying to put
humans on the surface of Phobos than trying to put
them on the surface of Mars itself, because it's a
lot easier to get back from the surface of Phobos
than it is to get back from Mars itself. To
get off of the surface of Mars, you need a

(50:31):
powerful rocket to leave the gravity well of the planet.
Getting off of Phobos would be would be a cake
walk in comparison. Now, of course, putting humans or even
just probes on the surface of Phobos would still be
plenty difficult. And I was reading about one possible complication
that really fascinated me. This was in another NASA press
release that I was looking at from October of seventeen

(50:53):
by Bills Steagerwald and Nancy Jones, and it is about
research suggesting that solar eruptions may have a tendency to
electrically charge up the surface of Phobos two hundreds of
volts quote, presenting a complex electrical environment that could possibly
affect sensitive electronics carried by future robotic explorers, according to

(51:17):
a new NASA study. The study also considered electrical charges
that could develop as astronauts transit the surface on potential
human missions to Phobos, and they quote a researcher named
William Farrell of NASA Goddard who says, we found that
astronauts or rovers could accumulate significant electric charges when traversing

(51:40):
the night side of Phobos, the side facing Mars during
the Martian Day. So why would this happen? Why would
Phobos turn into a giant Ben Franklin Turkey killing jar. Well, fortunately,
the electric charge is not quite that powerful. I think
it is not at the Turkey killing jar levels. It
seems unlikely that it would be in human injury range

(52:01):
at least most of the time, but it might be
enough to screw up sensors and sensitive or delicate electronic equipment.
So what gives what would cause this? Well, Phobos and
Demos both have no atmosphere, and they are exposed to
solar wind, which is a giant stream of charged particles.
You can think of it as a kind of electric

(52:21):
gas that's blowing off of the surface of the Sun
in every direction at a million miles per hour. So
solar wind hits the day side of Phobos, that would
be the side that's facing the Sun, and some of
the plasma gets absorbed on the day side, but then
the rest flows around the rocky mass of Phobos, and

(52:42):
this creates a void of solar wind on the night
side of Phobos. And the solar wind is made up
of two major types of charge particles. You've got electrons,
which of course are negative, and then you've got ions
pieces of atoms that can be positively charged. And the
electrons are much lighter than the eons. So the article
again quotes William Farrell of NASA Goddard, who says, quote,

(53:05):
the electrons act like fighter jets. They're able to turn
quickly around an obstacle, and the ions are like big,
heavy bombers. They change directions slowly. This means that the
light electrons push in ahead of the heavy ions, and
the resulting electric field forces the ions into the plasma
void behind Phobos. According to our models, and so the

(53:27):
result is that the night side of Phobos builds up
significant static electricity. Quote. The study shows that this plasma
void behind Phobos may create a situation where astronauts and
rovers build up significant electric charges. For example, if astronauts
were to walk across the night side surface friction could

(53:48):
transfer charge from the dust and rock on the surface
to their space suits. This dust and rock is a
very poor conductor of electricity, so the charge can't flow
back easily into the surface, and charge starts to build
up on the space suits. On the day side, the
electrically conducting solar wind and solar ultra violet radiation can
remove the excess charge on the suit, but on the

(54:10):
night side, the ion and electron densities in the trailing
plasma void are so low they cannot compensate or dissipate
the charge build up. And so the team looked into
this and they found that the static charge could reach
up to ten thousand volts on some materials that would
be moving across the surface. And some of those materials
would include like the teflon suits that that astronauts have

(54:33):
used in the Apollo lunar missions. And of course this
leads so you build up a gigantic static electric charge
on your space suit and then you go and touch something.
It's like you know when when you you shuffle across
the carpet and then use zap your family members. They
also point out that this is always going to be
the case when solar wind is blowing onto Phobos, but
it's going to be especially bad during heavy sun weather,

(54:56):
such as in the wake of a coronal mass ejection.
So astronaut on the surface of Phobos might need I
don't know that they may need mitigation measures for this,
somehow to avoid accumulating static electricity in this way. I
was wondering, I was looking it up. Do they make
those anti static socks I've seen before? I don't know
if those actually work. Those might be a scam. I've

(55:16):
never really looked into it. Oh yeah, I mean, I
guess they'd be useful if you're touching a lot of
electronics and stuff, But if you're just like a kid,
they seemed like a horrible invention. Why would you take
this gift of static electricity away from them? Oh? I
know you. You like zapping people, don't you. Um? I
actually don't za people as much intentionally. But one thing

(55:39):
that my son and I have always enjoyed is if
the if an atmospheric conditions are right, he can go
down a slide at a playground and he'll build up
that electric charge on the way down, and then he
can give me a high five, and when he gets
to the bottom of the slide, and it will be
what we call an electric high five because it will

(55:59):
be an actually static shock to it. So I do
all if that a lot. Uh, you know, always a
hit with the kids. That's so beautiful, I'm gonna cry.
But as far as Phobos goes this, this whole scenario
you just a discussed here, it made me think like
this would be perfect. You have like a Phobos space Western,
kind of like the Sean Connery movie Outlander. Um, Outland

(56:20):
not Outlander, Yes, yes, the Killed TV show, uh, which
which is also entertaining. But now this is this is uh,
this is a space Western scenario where you have your
astronaut and he's been left for dead, uh, you know,
on the far side of Phobos. But he's not dead.
So he comes trooping back, walking across the waste land

(56:41):
of Phoebos, just building up static electricity with each vengeful
step until he can get back to the habitat and
uh and zap his killers or would be killers. Brutal. Yeah.
I don't know if the science completely works, but I
think there's enough science there that you could make it
work in in a science fiction property. Well hey, okay,

(57:02):
so we love the cool idea of the holo Phobos,
but there's not good evidence that it's actually true. Put
it in the science fiction movie. Uh, the there is
actually evidence that you get this electric build up on Phobos.
It's probably not enough to do the like electric weapon
idea you want to do, but they put it in
the science fiction movie. Yeah. Yeah, yeah, you use it
as a jumping off point to create your your your

(57:25):
science flavored fantasy. I'm all for that. All right, Well,
there you have it. We're gonna go ahead and close
out our look at the moons of marsh. We'll hope
you enjoyed this. We enjoyed it, and you know it's
a great opportunity to to bust out some planetary information,
to discuss mythology a bit. And uh, I guess the

(57:47):
big question is would you like us to continue this
journey now that we have started it again? Should we
move on to other moons? Other planets? Uh? You know,
even even planets that that don't have moons. I don't
know if we've I can't remember if we ever ever
on like a proper look at the planet Mercury. I
know we've looked at at Venus a few times, but
I don't know that we've really looked at at Mercury.

(58:08):
So may you know, maybe that's uh in the cards.
Let us know. We'd love to hear from you. In
the meantime, if you want to check out other episodes
of Stuff to Blow your Mind, well you can find
us anywhere you get your podcasts. Go to the Stuff
to Blow your Mind Podcasts feed you'll find core science
and culture episodes of Stuff to Blow Your Mind. On
Tuesdays and Thursdays, we publish artifacts on Wednesday's listener Mail

(58:30):
on Monday's Friday's that's when we bust out Weird how Cinema.
That's our time to just discuss some weird movies and
sometimes there's a little science sprinkled in there. And then
on the weekends we do a bit of a rerun.
I gotta catch them all huge things. As always to
our excellent audio producer Seth Nicholas Johnson. If you would
like to get in touch with us with feedback on
this episode or any other to suggest topic for the future,

(58:53):
just to say hello, you can email us at contact
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(59:13):
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