September 1, 2026 • 53 mins
In this series from Stuff to Blow Your Mind, Robert and Joe turn their attention to the innermost hellworld of our solar system: Mercury. Join them as they discuss the planetary science, exploration history, mythology and sci-fi of Earth’s smallest sibling.
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Speaker 1 (00:02):
Welcome to Stuff to Blow Your Mind, a production of iHeartRadio.
Speaker 2 (00:12):
Hey, welcome to Stuff to Blow Your Mind. My name
is Robert Lamb.
Speaker 3 (00:16):
And I'm Joe McCormick. And today we're back with the
third part in our series on the planet Mercury. In
the previous episodes, we talked about the extremes of Mercury.
It's the smallest planet, the innermost planet. and the one
with the fastest orbit. Not the hottest planet, but the
planet with the greatest extremes in temperature between day and night,
(00:37):
with the lead-meltingly hot day, kind of becomes a frying
pan under the sun, and then a deep freeze during
the night. We talked about how Mercury is arguably the
hardest planet in the solar system to get to from Earth,
despite the fact that it's relatively close, and that difficulty
(00:57):
comes from the fact that As you travel from Earth
down into the lower orbits of Venus and Mercury, your
spacecraft picks up incredible speed because of the sun's gravity.
So you have to find a way to shed that
excess orbital energy if you actually want to go into
orbit around Mercury or potentially do a soft landing on
(01:18):
the planet, the latter of which has still never been done.
As we talked about last time, NASA's Messenger probe had
to do a complicated series of breaking maneuvers using gravity
assists from Earth, Venus, and Mercury itself to get into
orbit around the planet in 2011. And it is still
the only mission so far to do so, though ESA
(01:41):
and JAXA have a mission called BepiColombo that is currently
on the way to Mercury right now using a similar
strategy of a combination of different breaking maneuvers and planetary assists.
That one is scheduled to arrive in November of this year,
so we're just Just a little bit ahead of the arrival.
And if there's any new science coming in when that
mission arrives, we may have to revisit Mercury again. So
(02:05):
in the first episode, we talked about the mythological namesake
of Mercury, the Roman god of messengers, travel, trade and commerce, thievery,
many other jobs. Somehow I think gymnastics and wrestling ended
up in there. And we talked about the surprising fact
that under just the right imaging conditions, the planet Mercury
actually has a tail, much like a comet. In the
(02:28):
last episode, we talked about science fiction that has imagined
beings living on Mercury, everything from Asimov and Vonnegut to
Clark Ashton Smith. And we talked about a paper that
explored the possibility that Mercury may have briefly long ago
actually had conditions that might allow habitability, might allow for life,
(02:49):
though scientists today think that the possibility for life as
we know it on Mercury is somewhere between extremely low
and zero. And that's for obvious reasons. Basically, no atmosphere,
no liquid water, and the temperature fluctuations are insane. We
also talked in the last episode about a giant impact
(03:11):
basin on the surface of Mercury called the Caloris Basin,
the hot bowl. A very interesting surface feature lives inside
that basin known as Pantheon Fosse, previously known as the spider,
which looks like a giant star-shaped pattern of radial claw marks.
I didn't say this in the episode, but I was
thinking about it since then. And it looks kind of
(03:32):
like Freddy Krueger tried to draw an asterisk. You know,
he's got the parallel.
Speaker 2 (03:36):
Yeah.
Speaker 3 (03:38):
And so we talked about a paper exploring different hypotheses
for the formation of the Pantheon Fosse, where the authors
ended up arguing that it was most likely caused by
stretching of the ground from some kind of doming that
happened under the surface, like sort of like blowing up
an area of the planet's crust like the skin of
a balloon. And we are back today to talk about
(04:00):
Mercury some more.
Speaker 2 (04:02):
All right. Well, what do we have next? I understand
you have something. Something else related to the surface, reading
the surface of Mercury.
Speaker 3 (04:09):
Right. I want to talk about some pretty nasty looking hollows,
but I'll get there in a roundabout way. So if
you look at Mercury, one of the first things you
might notice about it is that it is totally covered
in craters. It is much more heavily cratered than the
other rocky planets like Earth, Venus and Mars. The high
(04:31):
density of craters is similar to what you see on
the surface of Earth's moon or maybe on the moons
of Jupiter. Well, I mean, certain of the moons of Jupiter,
you know, the surface of Io, of course, the innermost
moon of Jupiter does not look like this because it gets,
you know, repaved by its geological activity. But it looks
like those outer moons of Jupiter like Ganymede and Callisto.
(04:53):
There are several reasons Mercury looks so banged up like
this compared to the other inner planets. First of all,
Mercury has no significant atmosphere, as we've talked about in
the previous episodes. A lot of people might not realize this,
but most objects from space that hit Earth never actually
(05:16):
hit Earth. Instead, they hit the atmosphere and then something
happens to them before they get to the ground. They
often burn up, disintegrate, break apart into small pieces or vaporize,
all of this happening in the air before they reach
the ground. Different objects have different probabilities of making it
through the atmosphere, like large rocky or metallic asteroids are
(05:39):
the most likely to hit the ground with big pieces
still intact. Smaller rocks tend to burn up and break apart.
Smaller comets or cometary fragments often vaporize. According to NASA,
on average, less than 5% of an incoming meteoroid actually
makes it to the ground. This is within the normal
(06:00):
size range, things that are smaller than a football field.
On Mercury, much like on the Earth's moon, there is
no such atmospheric padding. So an object on a collision
course with Mercury will hit. It will hit at high velocity.
And ironically, the impact of what are called micrometeoroids, little meteoroids,
(06:22):
is one of the main ways that the extremely thin
exosphere of Mercury, Mercury's faint suggestion of an atmosphere, it's
one of the ways that that is continuously regenerated. So
you have multiple factors like solar radiation and the solar
wind charged particles from the sun. And, you know, heating
(06:44):
and micrometeoroid impacts all working together to knock volatile atoms
free from the rocky surface of the planet. And then
they float up free above the surface, become part of
the exosphere, which, again, is nowhere near thick enough to
provide any breaking on incoming objects. As a side note,
(07:05):
I don't think we really got into this the other
day when we were talking about the difficulty of getting
probes into orbit around Mercury. But this lack of an
atmosphere is another reason it would be extremely hard to
achieve a soft landing on Mercury if we were ever
going to try to put a lander or rover down
(07:25):
on the surface. So this is in addition to how
hard it is just to get into orbit around Mercury
in the first place. Of course, objects in orbit around
planets are going really fast and they need to slow
down to land safely on a planet. When you descend
down toward the Earth from orbit around Earth, aerodynamic drag
(07:48):
from the atmosphere does a lot of work to slow
you down automatically. It's sort of a free braking system. Now, obviously,
it's not the only thing you need. You will have
other methods to get yourself safely to the ground because
even just like falling through the atmosphere, you will hit hard.
But it does a lot of the slowing you down,
(08:08):
just like the drag created by the atmosphere. No such
luck on Mercury. To get a soft landing, you need
to basically provide all of your own braking, which I
think would mostly be, if you were trying to put
a lander down, it would probably be propellant-based, retro rockets,
like we use when we're coming down on the surface
of Mars.
Speaker 2 (08:28):
Yeah, yeah. I mean, I guess working in your favor
would be less gravity, like a shallower gravity well with Mercury.
But yeah, no atmosphere is going to really be an
obstacle here as well.
Speaker 3 (08:41):
Right. So you have less acceleration due to gravity, but
you're starting at such a high speed anyway when you're
in orbit. That doesn't matter as much. What you really
need to do is slow down your speed of moving
through space.
Speaker 2 (08:55):
But it's like backing into a parking space, though. Once
you've done all that work, it is a little easier
to leave.
Speaker 3 (09:01):
Yeah. So that's one reason Mercury is so covered in
craters when you look at it. It doesn't have the
atmosphere to protect it like Earth does or like Venus does.
Another reason Mercury is so covered in craters is that
Mercury does not have major ongoing geologic resurfacing like Earth does.
(09:25):
On Earth, there are lots of processes that erase the
old texture of the surface. and spit out freshly paved landscapes.
These processes include plate tectonics, volcanic eruptions, and erosion caused
by water and wind. Billions of years ago, Mercury did
(09:46):
have large-scale resurfacing processes like lava flows, volcanic lava flows
at the surface, because you can even remember we talked
about an example of this in the last episode with
the evidence that the Caloris Basin, that huge impact crater,
on Mercury, was once flooded with molten lava after it
was formed. But Mercury doesn't have that anymore. It no
(10:07):
longer has major geologic resurfacing. So for the past few
billion years, mostly any crater that has been made has
been preserved, except for those that have been erased by
other craters. However, I want to put a caveat there.
From all this, you might assume that Mercury is, quote,
geologically dead, the way some people sometimes describe things like
(10:31):
Mars or Earth's moon. When people call a planet geologically dead,
they usually mean that the planet has cooled enough That
there are no longer major changes driven by heat or
other forces from the inside. And technically today, I think
planetary scientists would quibble about calling Mars or the moon
(10:52):
geologically dead because both of those bodies show signs of
some geological activity like quakes. You know, there are Mars
quakes and moon quakes and both have some younger surface features,
but they are both at least very low in geological
activity compared to Earth. So contrary to what you might assume,
Mercury is not geologically dead. It is still geologically active.
(11:17):
And we know this, especially from data gathered by the
MESSENGER probe, but it's active in a different way than
Earth is. So Mercury does not have plate tectonics, doesn't
have plates moving around like Earth does, and it no
longer seems to have volcanic eruptions, at least that we've
been able to detect. Instead, it has thermal contraction and
(11:42):
that is what it sounds like mercury is in fact
shrinking the planet is shrinking so as the interior of
mercury cools over the history you know the planet's geological
history the planet has been shrinking and as far as
we know is still shrinking and this results in visible
faults that you can see at the surface manifesting as
(12:04):
these kind of step-like cliffs or scarps I was looking
up exactly how much Mercury has shrunk. I found a
paper published in 2025 in AGU Advances by authors Stephan
Loveless and Christian Klimchak. And they estimated that Mercury's radius
has shrunk by at least three kilometers over the over
(12:26):
the geologic history of the planet. So not shrinking at
like an alarming rate. You're not going to see it
disappear in your lifetime. But as the planet continues to cool,
it is expected that it will continue to shrink. And
the signs of that will be visible in the rocky
crust getting a little bit more wrinkly. However, this all
brings me to the main thing I wanted to talk
(12:48):
about here, which are Mercury's hollows. I was reading about
these in an October 2023 NASA science article called Mercury's
Strange Hollows. This article had a little bit of a
Halloween flavoring. I appreciate the effort. They were trying to
link it to, you know, like Washington Irving in The
(13:09):
Legend of Sleepy Hollow. So the article talks about how
craters from space impacts are not the only depression marks
on Mercury's surface. Images like the ones returned by the
messenger probe show lots of places where the planet has
these patterns of depressions that the researchers call hollows. Rob,
(13:31):
I've got some pictures for you to look at in
the outline here. Folks at home, you can Google Mercury
hollows to see examples of this for yourself. I would
say from a distance. They're pits in the surface that
look sort of organic and diseased, like rotting meat or
like infected skin. Warning, I think these could possibly be a,
(13:53):
you know, tryptophobia trigger. People, if you don't like lotus pods,
you might not like looking at the mercury hollows. Some
of them also look like the mark left behind when
a xenomorph bleeds on the floor. Do you see that, Rob?
Speaker 2 (14:07):
Yeah, definitely. Definitely in these images that have a bit
more color applied to them, for sure. Yeah.
Speaker 3 (14:13):
Acid burn pattern uh there is a caustic irregular swarming
eaten away look so like something dissolved by acid or
or sort of uh you know eaten away by disease
uh and i've got some more images you can look
at here some hollows seen eating along the rim of
the poe crater which is named after edgar allen poe
(14:34):
you can see the blue area and the the white
here so according to this article uh These hollows are
found not just in one place. They're at a variety
of latitudes all over the planet. And they range greatly
in size from about 60 feet to about a mile across.
So that's about 18 to 1600 meters. And the ones
(14:56):
that we've documented are up to 80 feet or 24
meters deep. Multiple sources I was reading claimed that these
hollows are thought to be unique in our solar systems.
There are not really any other features like them in
rock on any known planet, moon, or rocky body. The
researchers here will later make a comparison to some patterns
(15:20):
you can see in ice on Mars, but not in rock.
So the question would be, what causes these pits? The
article cites a planetary geologist named David Blewett of the
Applied Physics Laboratory at Johns Hopkins. And he points out
that while on another planet, you might wonder if these
hollows are caused by erosion forces like wind or rain.
(15:43):
Of course, Mercury has nothing that can really cause erosion
like that. There's no significant atmosphere, no liquid water. So
you can rule that out. And then he just says
almost ominously, other forces must be at work. Must be
something we haven't seen.
Speaker 2 (15:57):
Sinister forces.
Speaker 3 (15:59):
So what does cause them, uh, There are some clues,
clues especially from data and images gathered by the messenger mission.
So the hollows are irregularly shaped and they're often surrounded
by what is called here bright material. So in a
lot of photos, Rob, if you want to scroll back
up and look at these images. The pits, the kind
(16:21):
of diseased, eaten away areas, often look like they are glowing.
They're surrounded on all sides by brighter material than the
rest of the surface. So it looks like an acid
burn with a halo, kind of a holy burn. The
hollows also appear to be some of the youngest features
on the planet's surface, younger than the impact craters where
(16:43):
they live. You can see that because of their texture
imposed on top of these older impact zones. Another clue
is that they are often found on or near the
central mountains or mounds that are in the inside of
an impact crater. And the article says, quote, these so-called
(17:03):
peak rings are thought to be made of material forced
up from the depths by an impact that formed the crater.
So you get this area where like long ago something
hit the planet and then it forces up this, you know,
uplifting of the soil, maybe bring stuff up from underground
into And then you get these pits all around it.
That's where the hollows form. The article summarizes the comments
(17:26):
of another researcher named Carolyn Ernst of Johns Hopkins APL.
And she says, when a large object hits Mercury, of course,
it does form a crater, but that's not the only thing.
It often sort of excavates material. So it will hit
and then throw up stuff from deep underground, stuff that
was once buried and covered underground. and now it is
(17:48):
exposed by the impact. So material that was maybe stable
when it was buried underground can become unstable when exposed
to the forces at the surface, like the sun. Extreme heat,
solar radiation, solar wind, all these forces imposed by the sun,
the dreadful sword of the sun, can reach down and
(18:11):
cause hollows by acting upon these churned-up deposits of material
that were previously protected underground. And then the article quotes
the researcher David Blewett again, saying, quote, certain minerals, for example,
those that contain sulfur and other volatiles, would be easily
vaporized by the onslaught of heat, solar wind, and micrometeoroids
(18:35):
that Mercury experiences on a daily basis. Perhaps sulfur is vaporizing,
leaving just the other minerals, and therefore weakening the rock
and making it spongier. Then the rock would crumble and
erode more readily, forming these depressions. So in a metaphorical way,
I think if this explanation is correct, it is a
(18:58):
little bit like the planet has diseased flesh caused by
an injury. So it's like an injury gouges and then
you have an infection there and it eats away the skin.
So the crater, you know, the impact acts like a
plow turning over the surface and It exposes material that
reacts unevenly to the sun. Some of that material is
(19:18):
evaporated and blasted into the exosphere, maybe eventually blasted out
into space in the tail of the planet. And it
leaves behind a weak, spongy landscape of rock, which crumbles
and collapses maybe when there's another micrometeoroid impact, and you
get these hollows. The article also mentions somewhat similar looking depressions,
(19:41):
not in rock, but in the carbon dioxide ice at
the south pole of Mars. This is dry ice that
has a kind of Swiss cheese look. I looked up
an image and put it in the outline so you
could see that here too, Rob. A similar kind of
diseased look in the ice. But again, to see this
on a rocky surface is pretty much unique. There are
(20:03):
not really any analogies that we know about within the
solar system. Hmm.
Speaker 2 (20:07):
Yeah, I was looking at this image of the South
Pole ice on Mars, and I don't think I'd seen
this image before, but I'm not sure I would have
recognized it out of context as even being related to
the Martian surface. It looks like a crafting sink that
has like a partial layer of dried paint on the
bottom of it. That's the sense I get from it.
(20:28):
Not so much the landscape of another planet.
Speaker 3 (20:32):
Well, You know, I liked thinking about these hollows as, okay,
so you're writing science fiction that's going to have people
walking around on Mercury. I liked these as a new
hazard you could add into the list, a kind of
unstable ground, right? You know, you might have an area
where the rock has become kind of spongy and brittle
and pumice-like because of the uneven evaporation of all of
(20:56):
these volatiles within it. And you may create a new
diseased patch, create a new pit by walking over it
and collapsing it. It's like a natural pitfall trap.
Speaker 2 (21:05):
Yeah, we need more hazards on Mercury. This Mercury RPG
you're envisioning here, I'd love to see the hazard table
that you roll on. All of them end in certain death.
Speaker 3 (21:17):
One more thing I just want to mention quickly before
we move on. This is not really related to the Hollows,
but just because it was also mentioned in this article
and I thought it was interesting. There's another... feature you
get on the surface of mercury that's a weird relic
of its geological history the fact that it used to
be more volcanically active and doesn't appear to be anymore
(21:37):
you get these phenomenon known as ghost craters where you
can have one crater that looks like a normal crater
like you might see on the moon you know it's
a big circular pit it's got a ring around the
outside maybe a mound in the middle and then nearby
you just have the faintest suggestion of a circle and
but it's not really a pit like a normal crater is.
(22:01):
So these appear to be places where there was once
a regular impact crater like the others, but it was
filled in by volcanic lava billions of years ago, leaving
only the outline of a crater behind, surrounded by younger
craters that remain craters. But here you've just got the
(22:21):
ghost of a crater. Wow.
Speaker 2 (22:23):
Fascinating. I love this. And, you know, I love that
at some point, Science writers just decided that Mercury is
going to be the Halloween planet with ghost craters and
Edgar Allan Poe crater and the hollows. Yeah, well, why not?
So one of the planets has to step up and
do it. Why not Mercury?
Speaker 3 (22:43):
It's got whimsical stuff, too. I think there's the Dr.
Seuss crater.
Speaker 2 (23:00):
Now, I want to take us back a little bit.
I want to talk about the origins of Mercury and
some of our theories regarding its formation, as well as
the ultimate doom of Mercury. Both of these are, depending
on which origin story you go with, begins in violence
and ends in violence. So, yeah, I don't think we
(23:20):
really discussed the formation of Mercury, at least not in
any amount of depth already, but One of the main
theories is that it formed, like many other cosmic bodies,
via the accretion of gas and dust pulled together by gravity,
all of it eventually snowballing into a planet. Obviously, this
is going to be the case to some degree, no
matter what. This is just how cosmic bodies form. We've
(23:44):
talked about this before in the show. And this would
have happened an estimated 4.5 billion years ago. Mercury, of course,
as we've touched on, has an unusually large metal-to-silicate ratio
compared to Venus or Earth and Mars. And so if
we're going with this formation theory, we ask the question, well,
what happened to the lighter elements? Well, then the answer
is that they're blown back by the ferocity of the
(24:07):
sun's furnace. It's just all blasted out and away from it,
same as why it doesn't have an atmosphere. But then
there's another theory, and that is that Mercury, as we
know it, which is like 60% to 70% iron, with
the planet's iron core taking up something like 60% to 85%
of its volume, as we've discussed, like so much iron.
(24:30):
One idea is that this is what's left of an
impact event that occurred when a massive protoplanet smashed into
the planet Mercury. And basically, this would mean that the
Mercury we know today is essentially the T800 planet, skeleton
(24:50):
that got, you know, that got all the flesh blasted
off of it in the Terminator. So I found this
interesting to think about. One of the more recent models
for this was outlined at Mark Thompson's A New Theory
Explains the Surprising Origin of the Planet Mercury, published in
Universe Today last year, covering a paper from the National
Observatory in Brazil. So this is one of those things where,
(25:12):
you know, scientists will We'll put together different models, trying
to figure out exactly how this would work from a
physics standpoint. But yeah, on one hand, either the planet
forms and it gets all this extra lighter stuff blasted
off of it, or there is an impact event that
just knocks all that stuff off of it and leaves
(25:33):
essentially like an iron core with very little additional material
on top of it.
Speaker 3 (25:38):
Interesting. Interesting.
Speaker 2 (25:40):
So, you know, one way or another, potentially violent past
for the planet. And then there's going to be a
violent end. There's really no way around this. So this
is likely a fact that many of you have heard before,
and you've probably heard it many times. And it concerns,
it actually concerns the long-term destiny of the planet Earth,
but also the planet Mercury. The idea is that Mercury
(26:03):
will eventually be consumed by the very sun it orbits.
already it's kind of a toxic relationship, right? The sun
is pretty harsh on Mercury, at least from our human
perspective on these things, and it's just going to get
more violent. As covered in multiple explainers, you'll find some
great explainers out there. I was looking at a couple,
one on astronomy.com, at least one hosted on NASA, in
(26:26):
roughly 5 billion years' time, so very far in the future.
Our sun will burn up its core hydrogen fuel and
start burning helium, And in doing so, it's going to
transform into a red giant. The atmosphere of the sun
is going to expand outwards to somewhere around the current
boundary mark of one astronomical unit. That, of course, is
(26:47):
bad news for us because an astronomical unit or AU is,
of course, the distance between our current sun and the Earth.
So if the sun grows that huge, it is going
to potentially come into contact or at least get way
closer to the Earth than we would like at all.
Speaker 3 (27:07):
So kind of coin flip as to whether the Earth
will be inside the sun or not?
Speaker 2 (27:11):
Yeah, that seems to, that's kind of like another one
of these areas where scientists will kind of like crunch
the math and throw out different projections. I was reading
a NASA multi-page article titled Life and Death of a
Planetary System. And in it, they quote one Dimitri Varis
of the University of Warwick. And He says, okay, Mercury
(27:33):
and Venus absolutely are going to be swallowed up. Like,
that's not in question at all. If our sun goes,
those two are gone. A little more detail on what
going would consist of. But Varus says, okay, Mars is
not going to be touched by this. But for Earth,
it's a little bit less clear. Of course, even if
(27:54):
the atmosphere of the sun doesn't physically overtake our planet, obviously,
The radiation blast alone would just render our planet completely uninhabitable. Yeah. Thus,
you know, it really doesn't matter at that point. Like
it's uninhabitable Earth after that point.
Speaker 1 (28:09):
Yeah.
Speaker 3 (28:10):
Yeah. So it's not like, oh, if we don't get
swallowed by the sun, then Earth will be fine at
that point. Right.
Speaker 2 (28:15):
Right. So, you know, as you've heard many times before,
I'm sure listeners at this point, you've read it, you've
heard it in your far future science fictions. You've heard
it from various futurists. But there's essentially a 5 billion
year ticking time bomb on our planet. True long-term survival
of humans and or just life itself on Earth, life
(28:38):
as we know it, for it to live on, we
would have to somehow seed a new place with it.
We would, or in some of our more fantastic visions,
like move the planet somewhere else, something would have to
happen because after this extensive amount of time, yeah, Earth
would be toast. Of course, five billion years is a
(29:00):
very long time, longer than the Earth has existed at all.
And there's room for any number of extinction events between
now and then of our own making cosmic in nature
or just, you know, complete outside context events as well
that we just can't even speculate on. So it's nothing
to lose sleep over. But it is one of those
(29:21):
things that is as humans, as dreamers, we can't help
but But think about it and say, well, what could
we do? How could we possibly prevent that ultimate end
of the story?
Speaker 3 (29:33):
Yeah, I think it's really compelling. It's compelling as a
thought because of its physical inevitability. like this is definitely
coming at some point it may be very very very
far in the future uh but i think if we're
being realistic about statistics and like you know where are
we most likely to encounter an extinction level event for
(29:53):
human beings i I don't think this is the first
thing to worry about. I think there are things going
to happen a lot sooner that are serious, you know, biological, technological, cultural,
climate-related problems that will probably be serious problems for humans
way before we reach like astronomical problems.
Speaker 2 (30:13):
Yeah, yeah, absolutely. And it's the kind of problem that
our current state of technology would not be able to solve.
This is one we really would have to lean on
on far future generations who conceivably have a much higher
state of technological achievement and could potentially do things like
(30:35):
move to other worlds or even in the more extremes
like move worlds. You know, godlike powers, really, from our
vantage point on the technological ladder. Now, as far as
Mercury goes, again, Mercury in this scenario, there's no question,
it gets swallowed up. But as far as how this
would actually go down for Mercury, there is still a
fair amount of discussion, like what would this look like? Um,
(30:56):
the surface would probably boil. Um, it would likely continue
to orbit the sun, but within the expanded atmosphere of
the sun, like it wouldn't just be swallowed up and
then gone like that, but it would be like, sort
of like pulled in, uh, it's melting, it's burning. Eventually
as it, as it moves towards the sun's core, it's like,
it's fractured, it's vaporized. So in a sense, it's like,
(31:18):
there is this digestion of mercury by the sun, if
you want to, apply a biological model to it. Either way,
it's toast. Mercury, as we know it, becomes nothing. It
just becomes part of the sun at that point.
Speaker 3 (31:33):
I shouldn't have bought property there.
Speaker 2 (31:34):
I know, I know. But, you know, five billion years out.
Speaker 3 (31:38):
That guy told me it was just going up.
Speaker 2 (31:41):
Unless, yeah, I guess if you're talking about moving planets,
so maybe you move Mercury too. Not sure. Music Now,
when it comes to the potential human applications for the
planet Mercury, again, we've touched on all of the risks
(32:05):
involved with this place and how harsh and extreme it is.
So we might wonder, well, what use would it be?
If it's so hostile, it's so hard to get to,
why bother with Mercury? Is there anything worth having there?
And that, of course, involves the basic, you know, human
exploitation drive to sort of look at these planets as
(32:27):
things that can and should be harvested. You know, what
good is it to us? What riches can we create
out of its surface? That sort of thing. And, you know,
you can, again, so that's the kind of thing you
can certainly criticize in and of itself. But when you
get into answering this question, of course, there are the metals.
But Is it the best place to potentially harvest metals
(32:51):
within our solar system? I think most experts on this
would argue no. Near-Earth metallic asteroids, or even our own moon,
are going to offer far more accessible options without these
various risks that we've already discussed.
Speaker 3 (33:08):
I mean, we've already talked about the extreme planning and
energy requirements just to get a probe to Mercury, and
that's one that doesn't have to come back. Trying to
imagine delivering payloads from Mercury to Earth, and it seems
like it'd be hard to make the math work out
right on that. Make it really profitable.
Speaker 2 (33:27):
Yeah, that's ultimately the big question with any of these
kind of megaproject considerations. It's like, at what point does
it actually make economic sense for you to do this?
It's one thing to ask, could we do it? But yeah,
what is the motivation? And what is it that would
make the math work out? If you're going to potentially
mine metals, on the surface of Mercury, why do you
(33:49):
need to do it there? What's going to happen there?
Is there some sort of answer? And in some cases,
there might be, according to some of these arguments we'll
get into. But on top of just the iron and
the metal that is to be found on Mercury, there
is the proximity to the sun, which certainly opens the
door for considerations of solar harvesting. So some of the
(34:10):
models you look at, you look at what people, will
be people saying, well, we could, you know, you could
build like solar farms on Mercury. And then harness the
energy there and in one form or another, like, supply
that energy back to Earth. And, of course, with any world, too,
we don't want to gloss over the fact that just
studying the planet would be, you know, vitally important. But
(34:34):
I guess we're more getting into these sort of, like,
what's in it for me, actually? Like, what can I
build out of it, right? Um, now one of the
more interesting ideas I ran across though, and this is,
this is the whole reason I was interested in even
looking at this question was that what if Mercury could
serve as a kind of travel hub? And some of
the ways that this could work, uh, come back to
(34:56):
all of that solar energy potential that we just touched on.
And we've also been discussing in terms of the thing
that is blasting the planet, um, And we also have
to factor in the planet's low escape velocity. Again, like
a much shallower gravity well. Obviously, you'd have to deal
with all the other dangers we've highlighted as well. But still,
(35:17):
there's a lot of solar energy, and it is a
planet that would theoretically be easier to escape from, just
in terms of taking off and entering Mercury's orbit. So
there's this idea that Mercury could serve as kind of a,
a hub for solar sail propulsion technology. So solar sails,
(35:38):
as we've discussed before, they work pretty much like the
sail of a ship, only instead of the wind pressing
on the sail, it's the photon particles of light transferring
their momentum to the sail. And of course, where are
these photons coming from? They're coming from our sun. So
the closer you are to the sun, the more a
solar sailing vessel can take advantage of those photons. And
(36:00):
as with sailing... by the wind on our own oceans,
you can go in either direction. You know, you can
sail into the wind, or in this case, sail into
the photons, I guess. Basically, a solar sail vessel approaching
the sun or Mercury would benefit from this proximity, which
is why you have some designs for Mercury-bound spacecraft that
(36:24):
have been designed but not executed with solar sail technology
in mind. The main one I was reading about is
the proposed NASA Mercury Scout which would reach Mercury, according
to their designs, on solar sails alone.
Speaker 3 (36:38):
Interesting.
Speaker 2 (36:39):
So, yeah, assuming you could build such craft on Mercury somehow,
perhaps via some sort of autonomous system that you've set up,
perhaps building them out of the metal and the various
resources that Mercury provides, you could then take advantage of
the planet's shallower gravity well, eject them into space, perhaps
(36:59):
via some sort of electromagnetic catapult. That seems to be
a favorite. And then they'd be in a prime location
to benefit from the radiation of the sun for propulsion.
High acceleration at first, less so as the craft would
travel away from the sun, but without any real slowdown
(37:20):
or resistance. This is one of the things that's often
highlighted about solar sail technology, is that It allows a
kind of continual acceleration. Thus, you would be able to
send something out from a hypothetical Mercury solar sail hub
out to the outer planets.
Speaker 3 (37:38):
Right. So unlike sailing on the water where the drag
from the water and the drag from the air will
slow you down over time if you don't continually apply pressure,
when you're sailing in space, you can just keep, it's
basically all additive. You can just keep adding up acceleration.
Speaker 1 (37:52):
Yeah.
Speaker 2 (37:54):
Now, another thing you'll see when you see discussion, when
you read about discussions of solar sail technology, and sometimes
we see this in our sci-fi as well. In a
weird way, it's actually depicted in the Tron movies. But
there's the idea that you could have a solar sail
vessel that is propelled not merely by photons from the sun,
(38:16):
but also some sort of like an emitted beam of
like laser energy. Yeah, yeah. And so this model is
also sometimes discussed with Mercury in mind, coming back to
the idea of using Mercury's high energy location to harvest
solar energy. And then what if you were able to
use that to then create this kind of like laser
(38:36):
highway that you could shoot these vessels out on?
Speaker 3 (38:39):
Okay, I see. So maybe on Mercury, you've got vast
fields of solar panels or something. You're harvesting a huge
amount of solar energy. Have a big reactor that turns
all that into a laser, and then you use the
pulses of laser to push things out into space in
the direction you want them to go, and that's your propulsion.
It's driven by some facility on the planet.
Speaker 2 (39:02):
Yeah, yeah. And so we see this at least visually
represented in the Tron movies, certainly the first one. I
think maybe they include it as like an Easter egg
in the second one, and I can't speak to the third.
Speaker 3 (39:12):
Hmm.
Speaker 2 (39:14):
But again, we have to ask questions like, why would
we do this? Is it really necessary? Is it worth
the investment that it would take to set up all
of this? There's a lot of what-ifs, like what if
we built a solar sail manufacturing base for robots? on
the surface of Mercury and so forth.
Speaker 3 (39:33):
I think of all these kinds of things as stuff
that could one day make sense if we got a
lot of other problems figured out.
Speaker 2 (39:40):
Yeah, we should just put it on the menu. We
don't know if anybody's going to order this, but we
need to have it listed just in case. Now, Another
interesting argument concerning Mercury is, of course, should we destroy
it and make a Dyson sphere out of it? Yes.
Speaker 3 (39:58):
Yes. I vote yes. Don't need any more details.
Speaker 2 (40:02):
This is like kind of the ultimate consideration of like, well,
let's just put it on the menu anyway, even though
why would we need this and so forth? And a
lot of this dates back to, of course, the Dyson
sphere is named for Freeman Dyson, who in the 1960s,
At one point, like in discussing Dyson spheres and Dyson
swarms and so forth, these ideas that you could, we've
(40:24):
discussed this on the show before, the idea that you
could put solar collectors around a star and in doing so,
like capture the energy potential of that star to power
your technology. And of course, Dyson is originally presenting this
not as a, hey, we should do this sort of thing,
but more of, if we're going to look for signs
of technologically advanced civilizations elsewhere, in our universe, what sort
(40:48):
of signs could we look for? What sort of dimming
of particular stars might signal the existence of some sort
of a megastructure like this? Right.
Speaker 3 (40:58):
So what if we look out there and instead of
seeing a star, we just see a lot of heat
exhaust coming out of a relatively dark place? That might
suggest that a star is being surrounded and harvested in
some way, and we're only seeing the waste coming off
of that superstructure.
Speaker 2 (41:14):
Yeah. So at one point, Dyson says, well, look at Mercury.
Mercury is exactly the sort of planet where you could
construct these solar collectors from materials on Mercury and deploy them.
And there have been more extreme takes on this in
recent decades. I was reading, I believe, Canadian futurist George
Dvorsky was arguing this in 2012. There's a lot of
(41:36):
activity around this in 2012. And there were some ideas
from Oxford physicist Stuart Armstrong along these lines as well,
where you wouldn't just make, let's say, a reasonable Dyson
swarm out of Mercury materials. You would build them out
of Mercury. You would basically destroy Mercury and make as
(41:59):
much of a Dyson swarm, almost a Dyson sphere, as
is physically possible, out of the remains of Mercury. So
destroy the planet, just absolutely Death Star the planet, And
then create solar harvesters out of that to power life
on Earth and, you know, I guess by this point,
other worlds as well. So, yeah, is it a good idea?
(42:23):
I mean, nobody's saying we should do this tomorrow. Obviously,
it's well beyond our capabilities. But at that time, 2012,
there was an article, at least this was on Forbes,
from Alex Knapp with Phil Plait. And they took this
idea to task, arguing that, look, from an energy standpoint alone,
just not practical. You'd have to put so much energy
(42:47):
into the destruction of Mercury. You wouldn't be able to
make back your money on this. You wouldn't be able
to recoup the loss, according to their math, for something
like 174 years. And the amount of energy that it
would take, again, is just well beyond anything we could
generate today. And then imagine what 174 years worth of
(43:11):
harvesting a large portion of the energy of our sun
would consist of like this. Just it's enormous. And how
would we even get that kind of like energy capital
to pull off the project to begin with?
Speaker 3 (43:25):
Yeah, we would kind of have to you would have
to be from a superhuman starting place.
Speaker 2 (43:30):
Yeah, we would have to be gifted this project from
some sort of alien civilization where they show up and
they're like, hey. Have you thought about destroying your innermost
planet and building something.
Speaker 3 (43:39):
Out of it?
Speaker 2 (43:40):
We'll pick up the bill for it if you're cool
with this. So, again, a lot of 2012 traffic on this.
I was reading another article in Popular Science from Rebecca
Boyle about it. And this author pointed out that we
face similar conundrums with transitions to sustainable energy. You know,
(44:02):
we want to burn less oil. But then we may
have to burn a little bit more oil to build
the technologies and infrastructures that ultimately free us from oil.
But still, that being said, the mercury Dyson sphere gambit
just doesn't work out on paper when we start crunching
the numbers.
Speaker 3 (44:18):
Yeah, I see the comparison, but it's worth being clear
that the Dyson swarm build out is a much crazier
relative proposition than like, yes, it is true that you
have to like spend to make. And that's true with
renewable energy as well. But that's a very doable project.
With commitment, that is realistic. Much bigger question about the
(44:39):
Mercury thing.
Speaker 2 (44:40):
Yeah, yeah. Now, another interesting question is, of course, if
this were to happen, if future, far future generations said, yeah,
we're doing it, we're destroying Mercury, We're making a Dyson
(45:02):
swarm out of it, and we're going to use that
to power the Earth. First of all, what does that
mean to destroy a planet, destroy the innermost planet of
our solar system? Because to a large degree, it seems
entirely egotistical and short-sighted to think that would have no
effect on the rest of the solar system and on Earth.
(45:24):
And certainly, I think there are arguments to be made.
you know, concerning the shrapnel from such an event, depending
on like how you cracked the planet and so forth.
But I was reading a little bit more about this,
and this was a Medium article that I thought was
rather good by one Omar V. Farrow titled, What Happens
If We Dismantle Mercury? And the author argues that, you know,
there wouldn't be much in the way of immediate consequences
(45:46):
for other planets. You know, it wouldn't really be a
blip in terms of like impacting, you know, the orbit
of Earth or you know, environmental or climate-based scenarios on Earth.
But there would be perhaps much longer term ramifications that
(46:07):
it would, quote, slightly rearrange the resonant structure of the
inner solar system, which could induce enhanced orbital chaos over
the course of, say, a billion years or so. So
Farrow says, quote, no instant apocalypse, just a slow increase
in orbital drama. But the other question, of course, is
what does it mean for the Earth, right? If you're
(46:28):
going to maybe not encase the sun completely in some
sort of a solid Dyson sphere like out of Star Trek,
which I think many people point out would certainly have
design limitations and might not be possible at all. But
if you were to swarm the sun with these solar harvesters,
(46:49):
you're going to potentially engage, you're going to engage in
the very sort of dimming, and cooling that certainly this
is a very dimming that like Dyson was originally talking about,
you know, this is the kind of thing that would,
that he's saying would be visible, would be observable one
way or the other to us, like across vast astronomical distances.
(47:10):
And so if you, if you swarmed our sun with
these solar collectors, less sunlight would reach our planet. And the,
the ramifications of that would be apocalyptic in the short term.
You were talking, you know, rapid cooling of the planet
and all manner of things. So, you know, it's hard
to you'd have to do so much additional sci fi
(47:30):
legwork to say, well, why are we doing why does
it make sense for us to get all of this
energy if we're dooming our own world in the process?
Not that that sort of problem has stopped before, but
but I don't know. It's still fun to think about
these ideas, I guess.
Speaker 3 (47:45):
I'm going to do a compromise. I say we should
put this on the back burner for two billion years
and then we come back to it and see if
it makes sense. Yeah. Yeah.
Speaker 2 (47:54):
I guess, I mean, one of the when we were
talking about these sorts of swarms, I mean, it does
factor into these sort of these very apocalyptic scenarios of like,
what if there was an alien civilization that came to
our solar system, you know, physically or via machines and
was like, hey, nice sun you've got there. we're going
to swarm it. Maybe we'll crack your inner planet to
(48:15):
make the swarm. And we're going to go ahead and
harvest that energy because we don't care about how much
sunlight is hitting the earth. We just want the energy
that's produced by your sun, just as we care about
the energy produced by various other suns out there. Collect
it all, put it onto a giant battery, and then
you ship that battery out to the home world. Perfect.
(48:38):
So anyway, again, all of that is very much getting
into a very... What can Mercury do for me? Well,
how can we consume Mercury's sort of viewpoint? But again,
a lot of like the reasons to actually send any
kind of spacecraft to Mercury, certainly at this stage in
our knowledge of our own solar system, is just to
learn more about it. There's just so many more mysteries
(48:58):
about the planet that need solving. There's so much more
data to be learned, so much to learn about our
own sun as well, potentially via some sort of at
least probe-based occupation of Mercury.
Speaker 3 (49:10):
Is anybody talking about eating it?
Speaker 2 (49:12):
Is it edible? I don't believe it is edible.
Speaker 3 (49:16):
Is that one of those out there?
Speaker 2 (49:16):
I mean, it's rich in iron, but there are better
ways to get your daily iron than by consuming mercury.
Speaker 3 (49:21):
What if we ate mercury? Yeah. How about, you know,
I have a hard time finding a parking space a
lot of times. What if we turn it into extra parking,
take some of that pressure off of our cities?
Speaker 2 (49:33):
Yeah, yeah, yeah.
Speaker 3 (49:34):
Some overflow lots on mercury.
Speaker 2 (49:36):
Again, coming back to like how we treat Mercury and sci-fi,
I think it's telling that more of our recent science
fiction visions, even if you end up putting a lot
of people on Mercury for one reason or another, like
it basically turns out like, Oh yeah, they're just, they're
mining stuff. Like that's all they're doing maybe, or maybe
a research station, but we, you know, nobody's like even
(49:57):
in sci-fi giving much attention to the idea of, of
turning it into anything else of, of use to us. Uh,
but I think the, like the, the, um, The solar
sail transport hub is perhaps one of the more enticing
ideas I've heard.
Speaker 3 (50:11):
Every time we do one of these series about space,
about other planets or moons, I notice that it just
makes me feel very emotionally attached to Earth. You know,
you can appreciate what's cool and fascinating and beautiful even
or creepy about other planets like they can really arrest
(50:32):
the attention for a short time. Often by the end
of that time, I really just want to go outside
and walk in the grass and see a tree.
Speaker 2 (50:40):
Yeah, I mean, when you get into discussing just how
inhospitable these other worlds in our own solar system are,
you know, it just drives home how special our Earth is. Where, again,
like even on our Earth, there are parts of it
where we cannot live without a great deal of technological help.
You know, like we can't live at the poles without
(51:01):
a great deal of help and a lot of technological support.
But even those parts of our world are far more
hospitable to, say, the surface of Mars or the surface
of the moon or certainly the surface of Mercury.
Speaker 3 (51:13):
We've got a really good thing going here.
Speaker 2 (51:16):
Yeah, let's not screw it up anymore, right?
Speaker 3 (51:19):
Are we doing another episode on Mercury or not? Do
we not know yet? Should we leave that open?
Speaker 2 (51:22):
I think we're going to leave it open because we
haven't completely decided. I think there are some more potential
topics to discuss. We'll just have to figure that out
after we finish recording here.
Speaker 3 (51:33):
Okay. So, folks, next time's going to be a surprise.
Either more Mercury or something else.
Speaker 2 (51:38):
Yeah. But either way, you know, write in with your
thoughts about this episode. Write in about any topic related
to Mercury we didn't cover. That includes, you know, the
hard science of the matter or sci-fi visions related to Mercury,
references in the media. We'd love to hear any of it.
We'll just remind you that Stuff to Blow Your Mind
(51:58):
is primarily a science and culture podcast with core episodes
on Tuesdays and Thursdays, short form on Wednesdays. And on Fridays,
we set aside most serious concerns to just talk about
a weird film on Weird House Cinema. However you get
the show, we just ask that you rate, review, and
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(52:21):
thumbs up. Ask to be reminded about new episodes. That
helps us out.
Speaker 3 (52:25):
Huge thanks, as always, to our excellent audio producer, J.J. Poswave.
If you would like to get in touch with us
with feedback on this episode or any other, to suggest
a topic for the future, or just to say hello,
you can email us at contact at StuffedBlowYourMind.com.
Speaker 1 (52:40):
Stuffed Blow Your Mind is a production of iHeartRadio. For
more podcasts from iHeartRadio, visit the iHeartRadio app. Apple Podcasts
are wherever you listen to your favorite shows.
Speaker 2 (53:03):
Thank you.
Welcome to Stuff to Blow Your Mind, a production of iHeartRadio.
Speaker 2 (00:12):
Hey, welcome to Stuff to Blow Your Mind. My name
is Robert Lamb.
Speaker 3 (00:16):
And I'm Joe McCormick. And today we're back with the
third part in our series on the planet Mercury. In
the previous episodes, we talked about the extremes of Mercury.
It's the smallest planet, the innermost planet. and the one
with the fastest orbit. Not the hottest planet, but the
planet with the greatest extremes in temperature between day and night,
(00:37):
with the lead-meltingly hot day, kind of becomes a frying
pan under the sun, and then a deep freeze during
the night. We talked about how Mercury is arguably the
hardest planet in the solar system to get to from Earth,
despite the fact that it's relatively close, and that difficulty
(00:57):
comes from the fact that As you travel from Earth
down into the lower orbits of Venus and Mercury, your
spacecraft picks up incredible speed because of the sun's gravity.
So you have to find a way to shed that
excess orbital energy if you actually want to go into
orbit around Mercury or potentially do a soft landing on
(01:18):
the planet, the latter of which has still never been done.
As we talked about last time, NASA's Messenger probe had
to do a complicated series of breaking maneuvers using gravity
assists from Earth, Venus, and Mercury itself to get into
orbit around the planet in 2011. And it is still
the only mission so far to do so, though ESA
(01:41):
and JAXA have a mission called BepiColombo that is currently
on the way to Mercury right now using a similar
strategy of a combination of different breaking maneuvers and planetary assists.
That one is scheduled to arrive in November of this year,
so we're just Just a little bit ahead of the arrival.
And if there's any new science coming in when that
mission arrives, we may have to revisit Mercury again. So
(02:05):
in the first episode, we talked about the mythological namesake
of Mercury, the Roman god of messengers, travel, trade and commerce, thievery,
many other jobs. Somehow I think gymnastics and wrestling ended
up in there. And we talked about the surprising fact
that under just the right imaging conditions, the planet Mercury
actually has a tail, much like a comet. In the
(02:28):
last episode, we talked about science fiction that has imagined
beings living on Mercury, everything from Asimov and Vonnegut to
Clark Ashton Smith. And we talked about a paper that
explored the possibility that Mercury may have briefly long ago
actually had conditions that might allow habitability, might allow for life,
(02:49):
though scientists today think that the possibility for life as
we know it on Mercury is somewhere between extremely low
and zero. And that's for obvious reasons. Basically, no atmosphere,
no liquid water, and the temperature fluctuations are insane. We
also talked in the last episode about a giant impact
(03:11):
basin on the surface of Mercury called the Caloris Basin,
the hot bowl. A very interesting surface feature lives inside
that basin known as Pantheon Fosse, previously known as the spider,
which looks like a giant star-shaped pattern of radial claw marks.
I didn't say this in the episode, but I was
thinking about it since then. And it looks kind of
(03:32):
like Freddy Krueger tried to draw an asterisk. You know,
he's got the parallel.
Speaker 2 (03:36):
Yeah.
Speaker 3 (03:38):
And so we talked about a paper exploring different hypotheses
for the formation of the Pantheon Fosse, where the authors
ended up arguing that it was most likely caused by
stretching of the ground from some kind of doming that
happened under the surface, like sort of like blowing up
an area of the planet's crust like the skin of
a balloon. And we are back today to talk about
(04:00):
Mercury some more.
Speaker 2 (04:02):
All right. Well, what do we have next? I understand
you have something. Something else related to the surface, reading
the surface of Mercury.
Speaker 3 (04:09):
Right. I want to talk about some pretty nasty looking hollows,
but I'll get there in a roundabout way. So if
you look at Mercury, one of the first things you
might notice about it is that it is totally covered
in craters. It is much more heavily cratered than the
other rocky planets like Earth, Venus and Mars. The high
(04:31):
density of craters is similar to what you see on
the surface of Earth's moon or maybe on the moons
of Jupiter. Well, I mean, certain of the moons of Jupiter,
you know, the surface of Io, of course, the innermost
moon of Jupiter does not look like this because it gets,
you know, repaved by its geological activity. But it looks
like those outer moons of Jupiter like Ganymede and Callisto.
(04:53):
There are several reasons Mercury looks so banged up like
this compared to the other inner planets. First of all,
Mercury has no significant atmosphere, as we've talked about in
the previous episodes. A lot of people might not realize this,
but most objects from space that hit Earth never actually
(05:16):
hit Earth. Instead, they hit the atmosphere and then something
happens to them before they get to the ground. They
often burn up, disintegrate, break apart into small pieces or vaporize,
all of this happening in the air before they reach
the ground. Different objects have different probabilities of making it
through the atmosphere, like large rocky or metallic asteroids are
(05:39):
the most likely to hit the ground with big pieces
still intact. Smaller rocks tend to burn up and break apart.
Smaller comets or cometary fragments often vaporize. According to NASA,
on average, less than 5% of an incoming meteoroid actually
makes it to the ground. This is within the normal
(06:00):
size range, things that are smaller than a football field.
On Mercury, much like on the Earth's moon, there is
no such atmospheric padding. So an object on a collision
course with Mercury will hit. It will hit at high velocity.
And ironically, the impact of what are called micrometeoroids, little meteoroids,
(06:22):
is one of the main ways that the extremely thin
exosphere of Mercury, Mercury's faint suggestion of an atmosphere, it's
one of the ways that that is continuously regenerated. So
you have multiple factors like solar radiation and the solar
wind charged particles from the sun. And, you know, heating
(06:44):
and micrometeoroid impacts all working together to knock volatile atoms
free from the rocky surface of the planet. And then
they float up free above the surface, become part of
the exosphere, which, again, is nowhere near thick enough to
provide any breaking on incoming objects. As a side note,
(07:05):
I don't think we really got into this the other
day when we were talking about the difficulty of getting
probes into orbit around Mercury. But this lack of an
atmosphere is another reason it would be extremely hard to
achieve a soft landing on Mercury if we were ever
going to try to put a lander or rover down
(07:25):
on the surface. So this is in addition to how
hard it is just to get into orbit around Mercury
in the first place. Of course, objects in orbit around
planets are going really fast and they need to slow
down to land safely on a planet. When you descend
down toward the Earth from orbit around Earth, aerodynamic drag
(07:48):
from the atmosphere does a lot of work to slow
you down automatically. It's sort of a free braking system. Now, obviously,
it's not the only thing you need. You will have
other methods to get yourself safely to the ground because
even just like falling through the atmosphere, you will hit hard.
But it does a lot of the slowing you down,
(08:08):
just like the drag created by the atmosphere. No such
luck on Mercury. To get a soft landing, you need
to basically provide all of your own braking, which I
think would mostly be, if you were trying to put
a lander down, it would probably be propellant-based, retro rockets,
like we use when we're coming down on the surface
of Mars.
Speaker 2 (08:28):
Yeah, yeah. I mean, I guess working in your favor
would be less gravity, like a shallower gravity well with Mercury.
But yeah, no atmosphere is going to really be an
obstacle here as well.
Speaker 3 (08:41):
Right. So you have less acceleration due to gravity, but
you're starting at such a high speed anyway when you're
in orbit. That doesn't matter as much. What you really
need to do is slow down your speed of moving
through space.
Speaker 2 (08:55):
But it's like backing into a parking space, though. Once
you've done all that work, it is a little easier
to leave.
Speaker 3 (09:01):
Yeah. So that's one reason Mercury is so covered in
craters when you look at it. It doesn't have the
atmosphere to protect it like Earth does or like Venus does.
Another reason Mercury is so covered in craters is that
Mercury does not have major ongoing geologic resurfacing like Earth does.
(09:25):
On Earth, there are lots of processes that erase the
old texture of the surface. and spit out freshly paved landscapes.
These processes include plate tectonics, volcanic eruptions, and erosion caused
by water and wind. Billions of years ago, Mercury did
(09:46):
have large-scale resurfacing processes like lava flows, volcanic lava flows
at the surface, because you can even remember we talked
about an example of this in the last episode with
the evidence that the Caloris Basin, that huge impact crater,
on Mercury, was once flooded with molten lava after it
was formed. But Mercury doesn't have that anymore. It no
(10:07):
longer has major geologic resurfacing. So for the past few
billion years, mostly any crater that has been made has
been preserved, except for those that have been erased by
other craters. However, I want to put a caveat there.
From all this, you might assume that Mercury is, quote,
geologically dead, the way some people sometimes describe things like
(10:31):
Mars or Earth's moon. When people call a planet geologically dead,
they usually mean that the planet has cooled enough That
there are no longer major changes driven by heat or
other forces from the inside. And technically today, I think
planetary scientists would quibble about calling Mars or the moon
(10:52):
geologically dead because both of those bodies show signs of
some geological activity like quakes. You know, there are Mars
quakes and moon quakes and both have some younger surface features,
but they are both at least very low in geological
activity compared to Earth. So contrary to what you might assume,
Mercury is not geologically dead. It is still geologically active.
(11:17):
And we know this, especially from data gathered by the
MESSENGER probe, but it's active in a different way than
Earth is. So Mercury does not have plate tectonics, doesn't
have plates moving around like Earth does, and it no
longer seems to have volcanic eruptions, at least that we've
been able to detect. Instead, it has thermal contraction and
(11:42):
that is what it sounds like mercury is in fact
shrinking the planet is shrinking so as the interior of
mercury cools over the history you know the planet's geological
history the planet has been shrinking and as far as
we know is still shrinking and this results in visible
faults that you can see at the surface manifesting as
(12:04):
these kind of step-like cliffs or scarps I was looking
up exactly how much Mercury has shrunk. I found a
paper published in 2025 in AGU Advances by authors Stephan
Loveless and Christian Klimchak. And they estimated that Mercury's radius
has shrunk by at least three kilometers over the over
(12:26):
the geologic history of the planet. So not shrinking at
like an alarming rate. You're not going to see it
disappear in your lifetime. But as the planet continues to cool,
it is expected that it will continue to shrink. And
the signs of that will be visible in the rocky
crust getting a little bit more wrinkly. However, this all
brings me to the main thing I wanted to talk
(12:48):
about here, which are Mercury's hollows. I was reading about
these in an October 2023 NASA science article called Mercury's
Strange Hollows. This article had a little bit of a
Halloween flavoring. I appreciate the effort. They were trying to
link it to, you know, like Washington Irving in The
(13:09):
Legend of Sleepy Hollow. So the article talks about how
craters from space impacts are not the only depression marks
on Mercury's surface. Images like the ones returned by the
messenger probe show lots of places where the planet has
these patterns of depressions that the researchers call hollows. Rob,
(13:31):
I've got some pictures for you to look at in
the outline here. Folks at home, you can Google Mercury
hollows to see examples of this for yourself. I would
say from a distance. They're pits in the surface that
look sort of organic and diseased, like rotting meat or
like infected skin. Warning, I think these could possibly be a,
(13:53):
you know, tryptophobia trigger. People, if you don't like lotus pods,
you might not like looking at the mercury hollows. Some
of them also look like the mark left behind when
a xenomorph bleeds on the floor. Do you see that, Rob?
Speaker 2 (14:07):
Yeah, definitely. Definitely in these images that have a bit
more color applied to them, for sure. Yeah.
Speaker 3 (14:13):
Acid burn pattern uh there is a caustic irregular swarming
eaten away look so like something dissolved by acid or
or sort of uh you know eaten away by disease
uh and i've got some more images you can look
at here some hollows seen eating along the rim of
the poe crater which is named after edgar allen poe
(14:34):
you can see the blue area and the the white
here so according to this article uh These hollows are
found not just in one place. They're at a variety
of latitudes all over the planet. And they range greatly
in size from about 60 feet to about a mile across.
So that's about 18 to 1600 meters. And the ones
(14:56):
that we've documented are up to 80 feet or 24
meters deep. Multiple sources I was reading claimed that these
hollows are thought to be unique in our solar systems.
There are not really any other features like them in
rock on any known planet, moon, or rocky body. The
researchers here will later make a comparison to some patterns
(15:20):
you can see in ice on Mars, but not in rock.
So the question would be, what causes these pits? The
article cites a planetary geologist named David Blewett of the
Applied Physics Laboratory at Johns Hopkins. And he points out
that while on another planet, you might wonder if these
hollows are caused by erosion forces like wind or rain.
(15:43):
Of course, Mercury has nothing that can really cause erosion
like that. There's no significant atmosphere, no liquid water. So
you can rule that out. And then he just says
almost ominously, other forces must be at work. Must be
something we haven't seen.
Speaker 2 (15:57):
Sinister forces.
Speaker 3 (15:59):
So what does cause them, uh, There are some clues,
clues especially from data and images gathered by the messenger mission.
So the hollows are irregularly shaped and they're often surrounded
by what is called here bright material. So in a
lot of photos, Rob, if you want to scroll back
up and look at these images. The pits, the kind
(16:21):
of diseased, eaten away areas, often look like they are glowing.
They're surrounded on all sides by brighter material than the
rest of the surface. So it looks like an acid
burn with a halo, kind of a holy burn. The
hollows also appear to be some of the youngest features
on the planet's surface, younger than the impact craters where
(16:43):
they live. You can see that because of their texture
imposed on top of these older impact zones. Another clue
is that they are often found on or near the
central mountains or mounds that are in the inside of
an impact crater. And the article says, quote, these so-called
(17:03):
peak rings are thought to be made of material forced
up from the depths by an impact that formed the crater.
So you get this area where like long ago something
hit the planet and then it forces up this, you know,
uplifting of the soil, maybe bring stuff up from underground
into And then you get these pits all around it.
That's where the hollows form. The article summarizes the comments
(17:26):
of another researcher named Carolyn Ernst of Johns Hopkins APL.
And she says, when a large object hits Mercury, of course,
it does form a crater, but that's not the only thing.
It often sort of excavates material. So it will hit
and then throw up stuff from deep underground, stuff that
was once buried and covered underground. and now it is
(17:48):
exposed by the impact. So material that was maybe stable
when it was buried underground can become unstable when exposed
to the forces at the surface, like the sun. Extreme heat,
solar radiation, solar wind, all these forces imposed by the sun,
the dreadful sword of the sun, can reach down and
(18:11):
cause hollows by acting upon these churned-up deposits of material
that were previously protected underground. And then the article quotes
the researcher David Blewett again, saying, quote, certain minerals, for example,
those that contain sulfur and other volatiles, would be easily
vaporized by the onslaught of heat, solar wind, and micrometeoroids
(18:35):
that Mercury experiences on a daily basis. Perhaps sulfur is vaporizing,
leaving just the other minerals, and therefore weakening the rock
and making it spongier. Then the rock would crumble and
erode more readily, forming these depressions. So in a metaphorical way,
I think if this explanation is correct, it is a
(18:58):
little bit like the planet has diseased flesh caused by
an injury. So it's like an injury gouges and then
you have an infection there and it eats away the skin.
So the crater, you know, the impact acts like a
plow turning over the surface and It exposes material that
reacts unevenly to the sun. Some of that material is
(19:18):
evaporated and blasted into the exosphere, maybe eventually blasted out
into space in the tail of the planet. And it
leaves behind a weak, spongy landscape of rock, which crumbles
and collapses maybe when there's another micrometeoroid impact, and you
get these hollows. The article also mentions somewhat similar looking depressions,
(19:41):
not in rock, but in the carbon dioxide ice at
the south pole of Mars. This is dry ice that
has a kind of Swiss cheese look. I looked up
an image and put it in the outline so you
could see that here too, Rob. A similar kind of
diseased look in the ice. But again, to see this
on a rocky surface is pretty much unique. There are
(20:03):
not really any analogies that we know about within the
solar system. Hmm.
Speaker 2 (20:07):
Yeah, I was looking at this image of the South
Pole ice on Mars, and I don't think I'd seen
this image before, but I'm not sure I would have
recognized it out of context as even being related to
the Martian surface. It looks like a crafting sink that
has like a partial layer of dried paint on the
bottom of it. That's the sense I get from it.
(20:28):
Not so much the landscape of another planet.
Speaker 3 (20:32):
Well, You know, I liked thinking about these hollows as, okay,
so you're writing science fiction that's going to have people
walking around on Mercury. I liked these as a new
hazard you could add into the list, a kind of
unstable ground, right? You know, you might have an area
where the rock has become kind of spongy and brittle
and pumice-like because of the uneven evaporation of all of
(20:56):
these volatiles within it. And you may create a new
diseased patch, create a new pit by walking over it
and collapsing it. It's like a natural pitfall trap.
Speaker 2 (21:05):
Yeah, we need more hazards on Mercury. This Mercury RPG
you're envisioning here, I'd love to see the hazard table
that you roll on. All of them end in certain death.
Speaker 3 (21:17):
One more thing I just want to mention quickly before
we move on. This is not really related to the Hollows,
but just because it was also mentioned in this article
and I thought it was interesting. There's another... feature you
get on the surface of mercury that's a weird relic
of its geological history the fact that it used to
be more volcanically active and doesn't appear to be anymore
(21:37):
you get these phenomenon known as ghost craters where you
can have one crater that looks like a normal crater
like you might see on the moon you know it's
a big circular pit it's got a ring around the
outside maybe a mound in the middle and then nearby
you just have the faintest suggestion of a circle and
but it's not really a pit like a normal crater is.
(22:01):
So these appear to be places where there was once
a regular impact crater like the others, but it was
filled in by volcanic lava billions of years ago, leaving
only the outline of a crater behind, surrounded by younger
craters that remain craters. But here you've just got the
(22:21):
ghost of a crater. Wow.
Speaker 2 (22:23):
Fascinating. I love this. And, you know, I love that
at some point, Science writers just decided that Mercury is
going to be the Halloween planet with ghost craters and
Edgar Allan Poe crater and the hollows. Yeah, well, why not?
So one of the planets has to step up and
do it. Why not Mercury?
Speaker 3 (22:43):
It's got whimsical stuff, too. I think there's the Dr.
Seuss crater.
Speaker 2 (23:00):
Now, I want to take us back a little bit.
I want to talk about the origins of Mercury and
some of our theories regarding its formation, as well as
the ultimate doom of Mercury. Both of these are, depending
on which origin story you go with, begins in violence
and ends in violence. So, yeah, I don't think we
(23:20):
really discussed the formation of Mercury, at least not in
any amount of depth already, but One of the main
theories is that it formed, like many other cosmic bodies,
via the accretion of gas and dust pulled together by gravity,
all of it eventually snowballing into a planet. Obviously, this
is going to be the case to some degree, no
matter what. This is just how cosmic bodies form. We've
(23:44):
talked about this before in the show. And this would
have happened an estimated 4.5 billion years ago. Mercury, of course,
as we've touched on, has an unusually large metal-to-silicate ratio
compared to Venus or Earth and Mars. And so if
we're going with this formation theory, we ask the question, well,
what happened to the lighter elements? Well, then the answer
is that they're blown back by the ferocity of the
(24:07):
sun's furnace. It's just all blasted out and away from it,
same as why it doesn't have an atmosphere. But then
there's another theory, and that is that Mercury, as we
know it, which is like 60% to 70% iron, with
the planet's iron core taking up something like 60% to 85%
of its volume, as we've discussed, like so much iron.
(24:30):
One idea is that this is what's left of an
impact event that occurred when a massive protoplanet smashed into
the planet Mercury. And basically, this would mean that the
Mercury we know today is essentially the T800 planet, skeleton
(24:50):
that got, you know, that got all the flesh blasted
off of it in the Terminator. So I found this
interesting to think about. One of the more recent models
for this was outlined at Mark Thompson's A New Theory
Explains the Surprising Origin of the Planet Mercury, published in
Universe Today last year, covering a paper from the National
Observatory in Brazil. So this is one of those things where,
(25:12):
you know, scientists will We'll put together different models, trying
to figure out exactly how this would work from a
physics standpoint. But yeah, on one hand, either the planet
forms and it gets all this extra lighter stuff blasted
off of it, or there is an impact event that
just knocks all that stuff off of it and leaves
(25:33):
essentially like an iron core with very little additional material
on top of it.
Speaker 3 (25:38):
Interesting. Interesting.
Speaker 2 (25:40):
So, you know, one way or another, potentially violent past
for the planet. And then there's going to be a
violent end. There's really no way around this. So this
is likely a fact that many of you have heard before,
and you've probably heard it many times. And it concerns,
it actually concerns the long-term destiny of the planet Earth,
but also the planet Mercury. The idea is that Mercury
(26:03):
will eventually be consumed by the very sun it orbits.
already it's kind of a toxic relationship, right? The sun
is pretty harsh on Mercury, at least from our human
perspective on these things, and it's just going to get
more violent. As covered in multiple explainers, you'll find some
great explainers out there. I was looking at a couple,
one on astronomy.com, at least one hosted on NASA, in
(26:26):
roughly 5 billion years' time, so very far in the future.
Our sun will burn up its core hydrogen fuel and
start burning helium, And in doing so, it's going to
transform into a red giant. The atmosphere of the sun
is going to expand outwards to somewhere around the current
boundary mark of one astronomical unit. That, of course, is
(26:47):
bad news for us because an astronomical unit or AU is,
of course, the distance between our current sun and the Earth.
So if the sun grows that huge, it is going
to potentially come into contact or at least get way
closer to the Earth than we would like at all.
Speaker 3 (27:07):
So kind of coin flip as to whether the Earth
will be inside the sun or not?
Speaker 2 (27:11):
Yeah, that seems to, that's kind of like another one
of these areas where scientists will kind of like crunch
the math and throw out different projections. I was reading
a NASA multi-page article titled Life and Death of a
Planetary System. And in it, they quote one Dimitri Varis
of the University of Warwick. And He says, okay, Mercury
(27:33):
and Venus absolutely are going to be swallowed up. Like,
that's not in question at all. If our sun goes,
those two are gone. A little more detail on what
going would consist of. But Varus says, okay, Mars is
not going to be touched by this. But for Earth,
it's a little bit less clear. Of course, even if
(27:54):
the atmosphere of the sun doesn't physically overtake our planet, obviously,
The radiation blast alone would just render our planet completely uninhabitable. Yeah. Thus,
you know, it really doesn't matter at that point. Like
it's uninhabitable Earth after that point.
Speaker 1 (28:09):
Yeah.
Speaker 3 (28:10):
Yeah. So it's not like, oh, if we don't get
swallowed by the sun, then Earth will be fine at
that point. Right.
Speaker 2 (28:15):
Right. So, you know, as you've heard many times before,
I'm sure listeners at this point, you've read it, you've
heard it in your far future science fictions. You've heard
it from various futurists. But there's essentially a 5 billion
year ticking time bomb on our planet. True long-term survival
of humans and or just life itself on Earth, life
(28:38):
as we know it, for it to live on, we
would have to somehow seed a new place with it.
We would, or in some of our more fantastic visions,
like move the planet somewhere else, something would have to
happen because after this extensive amount of time, yeah, Earth
would be toast. Of course, five billion years is a
(29:00):
very long time, longer than the Earth has existed at all.
And there's room for any number of extinction events between
now and then of our own making cosmic in nature
or just, you know, complete outside context events as well
that we just can't even speculate on. So it's nothing
to lose sleep over. But it is one of those
(29:21):
things that is as humans, as dreamers, we can't help
but But think about it and say, well, what could
we do? How could we possibly prevent that ultimate end
of the story?
Speaker 3 (29:33):
Yeah, I think it's really compelling. It's compelling as a
thought because of its physical inevitability. like this is definitely
coming at some point it may be very very very
far in the future uh but i think if we're
being realistic about statistics and like you know where are
we most likely to encounter an extinction level event for
(29:53):
human beings i I don't think this is the first
thing to worry about. I think there are things going
to happen a lot sooner that are serious, you know, biological, technological, cultural,
climate-related problems that will probably be serious problems for humans
way before we reach like astronomical problems.
Speaker 2 (30:13):
Yeah, yeah, absolutely. And it's the kind of problem that
our current state of technology would not be able to solve.
This is one we really would have to lean on
on far future generations who conceivably have a much higher
state of technological achievement and could potentially do things like
(30:35):
move to other worlds or even in the more extremes
like move worlds. You know, godlike powers, really, from our
vantage point on the technological ladder. Now, as far as
Mercury goes, again, Mercury in this scenario, there's no question,
it gets swallowed up. But as far as how this
would actually go down for Mercury, there is still a
fair amount of discussion, like what would this look like? Um,
(30:56):
the surface would probably boil. Um, it would likely continue
to orbit the sun, but within the expanded atmosphere of
the sun, like it wouldn't just be swallowed up and
then gone like that, but it would be like, sort
of like pulled in, uh, it's melting, it's burning. Eventually
as it, as it moves towards the sun's core, it's like,
it's fractured, it's vaporized. So in a sense, it's like,
(31:18):
there is this digestion of mercury by the sun, if
you want to, apply a biological model to it. Either way,
it's toast. Mercury, as we know it, becomes nothing. It
just becomes part of the sun at that point.
Speaker 3 (31:33):
I shouldn't have bought property there.
Speaker 2 (31:34):
I know, I know. But, you know, five billion years out.
Speaker 3 (31:38):
That guy told me it was just going up.
Speaker 2 (31:41):
Unless, yeah, I guess if you're talking about moving planets,
so maybe you move Mercury too. Not sure. Music Now,
when it comes to the potential human applications for the
planet Mercury, again, we've touched on all of the risks
(32:05):
involved with this place and how harsh and extreme it is.
So we might wonder, well, what use would it be?
If it's so hostile, it's so hard to get to,
why bother with Mercury? Is there anything worth having there?
And that, of course, involves the basic, you know, human
exploitation drive to sort of look at these planets as
(32:27):
things that can and should be harvested. You know, what
good is it to us? What riches can we create
out of its surface? That sort of thing. And, you know,
you can, again, so that's the kind of thing you
can certainly criticize in and of itself. But when you
get into answering this question, of course, there are the metals.
But Is it the best place to potentially harvest metals
(32:51):
within our solar system? I think most experts on this
would argue no. Near-Earth metallic asteroids, or even our own moon,
are going to offer far more accessible options without these
various risks that we've already discussed.
Speaker 3 (33:08):
I mean, we've already talked about the extreme planning and
energy requirements just to get a probe to Mercury, and
that's one that doesn't have to come back. Trying to
imagine delivering payloads from Mercury to Earth, and it seems
like it'd be hard to make the math work out
right on that. Make it really profitable.
Speaker 2 (33:27):
Yeah, that's ultimately the big question with any of these
kind of megaproject considerations. It's like, at what point does
it actually make economic sense for you to do this?
It's one thing to ask, could we do it? But yeah,
what is the motivation? And what is it that would
make the math work out? If you're going to potentially
mine metals, on the surface of Mercury, why do you
(33:49):
need to do it there? What's going to happen there?
Is there some sort of answer? And in some cases,
there might be, according to some of these arguments we'll
get into. But on top of just the iron and
the metal that is to be found on Mercury, there
is the proximity to the sun, which certainly opens the
door for considerations of solar harvesting. So some of the
(34:10):
models you look at, you look at what people, will
be people saying, well, we could, you know, you could
build like solar farms on Mercury. And then harness the
energy there and in one form or another, like, supply
that energy back to Earth. And, of course, with any world, too,
we don't want to gloss over the fact that just
studying the planet would be, you know, vitally important. But
(34:34):
I guess we're more getting into these sort of, like,
what's in it for me, actually? Like, what can I
build out of it, right? Um, now one of the
more interesting ideas I ran across though, and this is,
this is the whole reason I was interested in even
looking at this question was that what if Mercury could
serve as a kind of travel hub? And some of
the ways that this could work, uh, come back to
(34:56):
all of that solar energy potential that we just touched on.
And we've also been discussing in terms of the thing
that is blasting the planet, um, And we also have
to factor in the planet's low escape velocity. Again, like
a much shallower gravity well. Obviously, you'd have to deal
with all the other dangers we've highlighted as well. But still,
(35:17):
there's a lot of solar energy, and it is a
planet that would theoretically be easier to escape from, just
in terms of taking off and entering Mercury's orbit. So
there's this idea that Mercury could serve as kind of a,
a hub for solar sail propulsion technology. So solar sails,
(35:38):
as we've discussed before, they work pretty much like the
sail of a ship, only instead of the wind pressing
on the sail, it's the photon particles of light transferring
their momentum to the sail. And of course, where are
these photons coming from? They're coming from our sun. So
the closer you are to the sun, the more a
solar sailing vessel can take advantage of those photons. And
(36:00):
as with sailing... by the wind on our own oceans,
you can go in either direction. You know, you can
sail into the wind, or in this case, sail into
the photons, I guess. Basically, a solar sail vessel approaching
the sun or Mercury would benefit from this proximity, which
is why you have some designs for Mercury-bound spacecraft that
(36:24):
have been designed but not executed with solar sail technology
in mind. The main one I was reading about is
the proposed NASA Mercury Scout which would reach Mercury, according
to their designs, on solar sails alone.
Speaker 3 (36:38):
Interesting.
Speaker 2 (36:39):
So, yeah, assuming you could build such craft on Mercury somehow,
perhaps via some sort of autonomous system that you've set up,
perhaps building them out of the metal and the various
resources that Mercury provides, you could then take advantage of
the planet's shallower gravity well, eject them into space, perhaps
(36:59):
via some sort of electromagnetic catapult. That seems to be
a favorite. And then they'd be in a prime location
to benefit from the radiation of the sun for propulsion.
High acceleration at first, less so as the craft would
travel away from the sun, but without any real slowdown
(37:20):
or resistance. This is one of the things that's often
highlighted about solar sail technology, is that It allows a
kind of continual acceleration. Thus, you would be able to
send something out from a hypothetical Mercury solar sail hub
out to the outer planets.
Speaker 3 (37:38):
Right. So unlike sailing on the water where the drag
from the water and the drag from the air will
slow you down over time if you don't continually apply pressure,
when you're sailing in space, you can just keep, it's
basically all additive. You can just keep adding up acceleration.
Speaker 1 (37:52):
Yeah.
Speaker 2 (37:54):
Now, another thing you'll see when you see discussion, when
you read about discussions of solar sail technology, and sometimes
we see this in our sci-fi as well. In a
weird way, it's actually depicted in the Tron movies. But
there's the idea that you could have a solar sail
vessel that is propelled not merely by photons from the sun,
(38:16):
but also some sort of like an emitted beam of
like laser energy. Yeah, yeah. And so this model is
also sometimes discussed with Mercury in mind, coming back to
the idea of using Mercury's high energy location to harvest
solar energy. And then what if you were able to
use that to then create this kind of like laser
(38:36):
highway that you could shoot these vessels out on?
Speaker 3 (38:39):
Okay, I see. So maybe on Mercury, you've got vast
fields of solar panels or something. You're harvesting a huge
amount of solar energy. Have a big reactor that turns
all that into a laser, and then you use the
pulses of laser to push things out into space in
the direction you want them to go, and that's your propulsion.
It's driven by some facility on the planet.
Speaker 2 (39:02):
Yeah, yeah. And so we see this at least visually
represented in the Tron movies, certainly the first one. I
think maybe they include it as like an Easter egg
in the second one, and I can't speak to the third.
Speaker 3 (39:12):
Hmm.
Speaker 2 (39:14):
But again, we have to ask questions like, why would
we do this? Is it really necessary? Is it worth
the investment that it would take to set up all
of this? There's a lot of what-ifs, like what if
we built a solar sail manufacturing base for robots? on
the surface of Mercury and so forth.
Speaker 3 (39:33):
I think of all these kinds of things as stuff
that could one day make sense if we got a
lot of other problems figured out.
Speaker 2 (39:40):
Yeah, we should just put it on the menu. We
don't know if anybody's going to order this, but we
need to have it listed just in case. Now, Another
interesting argument concerning Mercury is, of course, should we destroy
it and make a Dyson sphere out of it? Yes.
Speaker 3 (39:58):
Yes. I vote yes. Don't need any more details.
Speaker 2 (40:02):
This is like kind of the ultimate consideration of like, well,
let's just put it on the menu anyway, even though
why would we need this and so forth? And a
lot of this dates back to, of course, the Dyson
sphere is named for Freeman Dyson, who in the 1960s,
At one point, like in discussing Dyson spheres and Dyson
swarms and so forth, these ideas that you could, we've
(40:24):
discussed this on the show before, the idea that you
could put solar collectors around a star and in doing so,
like capture the energy potential of that star to power
your technology. And of course, Dyson is originally presenting this
not as a, hey, we should do this sort of thing,
but more of, if we're going to look for signs
of technologically advanced civilizations elsewhere, in our universe, what sort
(40:48):
of signs could we look for? What sort of dimming
of particular stars might signal the existence of some sort
of a megastructure like this? Right.
Speaker 3 (40:58):
So what if we look out there and instead of
seeing a star, we just see a lot of heat
exhaust coming out of a relatively dark place? That might
suggest that a star is being surrounded and harvested in
some way, and we're only seeing the waste coming off
of that superstructure.
Speaker 2 (41:14):
Yeah. So at one point, Dyson says, well, look at Mercury.
Mercury is exactly the sort of planet where you could
construct these solar collectors from materials on Mercury and deploy them.
And there have been more extreme takes on this in
recent decades. I was reading, I believe, Canadian futurist George
Dvorsky was arguing this in 2012. There's a lot of
(41:36):
activity around this in 2012. And there were some ideas
from Oxford physicist Stuart Armstrong along these lines as well,
where you wouldn't just make, let's say, a reasonable Dyson
swarm out of Mercury materials. You would build them out
of Mercury. You would basically destroy Mercury and make as
(41:59):
much of a Dyson swarm, almost a Dyson sphere, as
is physically possible, out of the remains of Mercury. So
destroy the planet, just absolutely Death Star the planet, And
then create solar harvesters out of that to power life
on Earth and, you know, I guess by this point,
other worlds as well. So, yeah, is it a good idea?
(42:23):
I mean, nobody's saying we should do this tomorrow. Obviously,
it's well beyond our capabilities. But at that time, 2012,
there was an article, at least this was on Forbes,
from Alex Knapp with Phil Plait. And they took this
idea to task, arguing that, look, from an energy standpoint alone,
just not practical. You'd have to put so much energy
(42:47):
into the destruction of Mercury. You wouldn't be able to
make back your money on this. You wouldn't be able
to recoup the loss, according to their math, for something
like 174 years. And the amount of energy that it
would take, again, is just well beyond anything we could
generate today. And then imagine what 174 years worth of
(43:11):
harvesting a large portion of the energy of our sun
would consist of like this. Just it's enormous. And how
would we even get that kind of like energy capital
to pull off the project to begin with?
Speaker 3 (43:25):
Yeah, we would kind of have to you would have
to be from a superhuman starting place.
Speaker 2 (43:30):
Yeah, we would have to be gifted this project from
some sort of alien civilization where they show up and
they're like, hey. Have you thought about destroying your innermost
planet and building something.
Speaker 3 (43:39):
Out of it?
Speaker 2 (43:40):
We'll pick up the bill for it if you're cool
with this. So, again, a lot of 2012 traffic on this.
I was reading another article in Popular Science from Rebecca
Boyle about it. And this author pointed out that we
face similar conundrums with transitions to sustainable energy. You know,
(44:02):
we want to burn less oil. But then we may
have to burn a little bit more oil to build
the technologies and infrastructures that ultimately free us from oil.
But still, that being said, the mercury Dyson sphere gambit
just doesn't work out on paper when we start crunching
the numbers.
Speaker 3 (44:18):
Yeah, I see the comparison, but it's worth being clear
that the Dyson swarm build out is a much crazier
relative proposition than like, yes, it is true that you
have to like spend to make. And that's true with
renewable energy as well. But that's a very doable project.
With commitment, that is realistic. Much bigger question about the
(44:39):
Mercury thing.
Speaker 2 (44:40):
Yeah, yeah. Now, another interesting question is, of course, if
this were to happen, if future, far future generations said, yeah,
we're doing it, we're destroying Mercury, We're making a Dyson
(45:02):
swarm out of it, and we're going to use that
to power the Earth. First of all, what does that
mean to destroy a planet, destroy the innermost planet of
our solar system? Because to a large degree, it seems
entirely egotistical and short-sighted to think that would have no
effect on the rest of the solar system and on Earth.
(45:24):
And certainly, I think there are arguments to be made.
you know, concerning the shrapnel from such an event, depending
on like how you cracked the planet and so forth.
But I was reading a little bit more about this,
and this was a Medium article that I thought was
rather good by one Omar V. Farrow titled, What Happens
If We Dismantle Mercury? And the author argues that, you know,
there wouldn't be much in the way of immediate consequences
(45:46):
for other planets. You know, it wouldn't really be a
blip in terms of like impacting, you know, the orbit
of Earth or you know, environmental or climate-based scenarios on Earth.
But there would be perhaps much longer term ramifications that
(46:07):
it would, quote, slightly rearrange the resonant structure of the
inner solar system, which could induce enhanced orbital chaos over
the course of, say, a billion years or so. So
Farrow says, quote, no instant apocalypse, just a slow increase
in orbital drama. But the other question, of course, is
what does it mean for the Earth, right? If you're
(46:28):
going to maybe not encase the sun completely in some
sort of a solid Dyson sphere like out of Star Trek,
which I think many people point out would certainly have
design limitations and might not be possible at all. But
if you were to swarm the sun with these solar harvesters,
(46:49):
you're going to potentially engage, you're going to engage in
the very sort of dimming, and cooling that certainly this
is a very dimming that like Dyson was originally talking about,
you know, this is the kind of thing that would,
that he's saying would be visible, would be observable one
way or the other to us, like across vast astronomical distances.
(47:10):
And so if you, if you swarmed our sun with
these solar collectors, less sunlight would reach our planet. And the,
the ramifications of that would be apocalyptic in the short term.
You were talking, you know, rapid cooling of the planet
and all manner of things. So, you know, it's hard
to you'd have to do so much additional sci fi
(47:30):
legwork to say, well, why are we doing why does
it make sense for us to get all of this
energy if we're dooming our own world in the process?
Not that that sort of problem has stopped before, but
but I don't know. It's still fun to think about
these ideas, I guess.
Speaker 3 (47:45):
I'm going to do a compromise. I say we should
put this on the back burner for two billion years
and then we come back to it and see if
it makes sense. Yeah. Yeah.
Speaker 2 (47:54):
I guess, I mean, one of the when we were
talking about these sorts of swarms, I mean, it does
factor into these sort of these very apocalyptic scenarios of like,
what if there was an alien civilization that came to
our solar system, you know, physically or via machines and
was like, hey, nice sun you've got there. we're going
to swarm it. Maybe we'll crack your inner planet to
(48:15):
make the swarm. And we're going to go ahead and
harvest that energy because we don't care about how much
sunlight is hitting the earth. We just want the energy
that's produced by your sun, just as we care about
the energy produced by various other suns out there. Collect
it all, put it onto a giant battery, and then
you ship that battery out to the home world. Perfect.
(48:38):
So anyway, again, all of that is very much getting
into a very... What can Mercury do for me? Well,
how can we consume Mercury's sort of viewpoint? But again,
a lot of like the reasons to actually send any
kind of spacecraft to Mercury, certainly at this stage in
our knowledge of our own solar system, is just to
learn more about it. There's just so many more mysteries
(48:58):
about the planet that need solving. There's so much more
data to be learned, so much to learn about our
own sun as well, potentially via some sort of at
least probe-based occupation of Mercury.
Speaker 3 (49:10):
Is anybody talking about eating it?
Speaker 2 (49:12):
Is it edible? I don't believe it is edible.
Speaker 3 (49:16):
Is that one of those out there?
Speaker 2 (49:16):
I mean, it's rich in iron, but there are better
ways to get your daily iron than by consuming mercury.
Speaker 3 (49:21):
What if we ate mercury? Yeah. How about, you know,
I have a hard time finding a parking space a
lot of times. What if we turn it into extra parking,
take some of that pressure off of our cities?
Speaker 2 (49:33):
Yeah, yeah, yeah.
Speaker 3 (49:34):
Some overflow lots on mercury.
Speaker 2 (49:36):
Again, coming back to like how we treat Mercury and sci-fi,
I think it's telling that more of our recent science
fiction visions, even if you end up putting a lot
of people on Mercury for one reason or another, like
it basically turns out like, Oh yeah, they're just, they're
mining stuff. Like that's all they're doing maybe, or maybe
a research station, but we, you know, nobody's like even
(49:57):
in sci-fi giving much attention to the idea of, of
turning it into anything else of, of use to us. Uh,
but I think the, like the, the, um, The solar
sail transport hub is perhaps one of the more enticing
ideas I've heard.
Speaker 3 (50:11):
Every time we do one of these series about space,
about other planets or moons, I notice that it just
makes me feel very emotionally attached to Earth. You know,
you can appreciate what's cool and fascinating and beautiful even
or creepy about other planets like they can really arrest
(50:32):
the attention for a short time. Often by the end
of that time, I really just want to go outside
and walk in the grass and see a tree.
Speaker 2 (50:40):
Yeah, I mean, when you get into discussing just how
inhospitable these other worlds in our own solar system are,
you know, it just drives home how special our Earth is. Where, again,
like even on our Earth, there are parts of it
where we cannot live without a great deal of technological help.
You know, like we can't live at the poles without
(51:01):
a great deal of help and a lot of technological support.
But even those parts of our world are far more
hospitable to, say, the surface of Mars or the surface
of the moon or certainly the surface of Mercury.
Speaker 3 (51:13):
We've got a really good thing going here.
Speaker 2 (51:16):
Yeah, let's not screw it up anymore, right?
Speaker 3 (51:19):
Are we doing another episode on Mercury or not? Do
we not know yet? Should we leave that open?
Speaker 2 (51:22):
I think we're going to leave it open because we
haven't completely decided. I think there are some more potential
topics to discuss. We'll just have to figure that out
after we finish recording here.
Speaker 3 (51:33):
Okay. So, folks, next time's going to be a surprise.
Either more Mercury or something else.
Speaker 2 (51:38):
Yeah. But either way, you know, write in with your
thoughts about this episode. Write in about any topic related
to Mercury we didn't cover. That includes, you know, the
hard science of the matter or sci-fi visions related to Mercury,
references in the media. We'd love to hear any of it.
We'll just remind you that Stuff to Blow Your Mind
(51:58):
is primarily a science and culture podcast with core episodes
on Tuesdays and Thursdays, short form on Wednesdays. And on Fridays,
we set aside most serious concerns to just talk about
a weird film on Weird House Cinema. However you get
the show, we just ask that you rate, review, and
subscribe on all those podcast outlets. And then if you
are watching on Netflix, which you can do, we have
the audio-video version on Netflix, give us a couple of
(52:21):
thumbs up. Ask to be reminded about new episodes. That
helps us out.
Speaker 3 (52:25):
Huge thanks, as always, to our excellent audio producer, J.J. Poswave.
If you would like to get in touch with us
with feedback on this episode or any other, to suggest
a topic for the future, or just to say hello,
you can email us at contact at StuffedBlowYourMind.com.
Speaker 1 (52:40):
Stuffed Blow Your Mind is a production of iHeartRadio. For
more podcasts from iHeartRadio, visit the iHeartRadio app. Apple Podcasts
are wherever you listen to your favorite shows.
Speaker 2 (53:03):
Thank you.
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Joe McCormick
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