Mars is very different from Earth, and yet it has certain things that make it similar...yet
still different.
Join us as we explore the reasons behind landslides on Mars.
9.
Why Do We Care About Landslides On Mars?
Usually, such phenomenon like landslides wouldn't get a lot of attention in the world.
After all, when it comes to landslides, they happen here on Earth, quite frequently in
fact.
And despite Mars being another planet, with its own kind of terrain and all that, it would
be very fair to say that landslides work the same over there because of the basic laws
of physics.
Sure, gravity is lesser there, and the atmosphere isn't as tight as our own, but that doesn't
mean that it can just have landslides that go outside the range of what we know to be
factual...right?
Except, scientists have noted that there have been many landslides that do indeed appear
to break the laws of physics.
No, I don't mean that they fall upwards or something of the like, but rather, how they
act when they become landslides is what has people curious.
In case you don't know, landslides are more than just falling rocks and dirt, they can
consume an area with its "flow", which is what happens once everything gets piled onto
one another.
The flow has a certain expected momentum, which is what people need to get out of the
way of if it's coming their way.
This is where the curious thing comes in, because some of the flows on Mars seem to
go on for a long ways.
MUCH longer than they would do on Earth, and they go so long that it makes it seem like
friction isn't even being applied to them.
How is this possible?
That's what we needed to find out, because if we were to colonize Mars, these kinds of
landslides could be a problem if they could reach us despite being very far away.
8.
What Causes These Landslides?
What might surprise is that these landslides, which are known as "Long Run-Out Landslides"
can also be found here on Earth at times, which makes it all the more weirder that they
seem to defy the laws of physics.
Especially since the volume of these landslides can not only be the size of the Empire State
Building, but go as fast as 224 miles per hour!
Yeah, try outrunning that...here's a hint, you can't.
Anyway, the biggest problem with these landslides is the seeming lack of friction here.
For those don't recall, friction is the natural resistance to movement.
If you have little friction you can slide and slide to your hearts content without stopping.
But with normal friction (like your feet on earth), the movement has to be motored by
your body as you won't go sliding anywhere.
Even on Mars, the force of Friction is evident, yet these landslides defy it.
A theory was put forward that there might have been ice where the landslides formed
at one point in time, and that amount of "lubrication" was able to make it so that the landslides
could flow on and on without an end for some time.
But, now scientists are thinking that this ISN'T the case.
Doing some tests on the kinds of ridges on Mars that had these landslides, they came
to realize that ice was not a factor in some of them, and wasn't even needed at times.
Rather, all it needed was the right amount of material...and convection.
7.
Convection What's that?
You don't remember what convection is?
Don't worry, here's the definition for you: "The movement caused within a fluid by the
tendency of hotter and therefore less dense material to rise, and colder, denser material
to sink under the influence of gravity, which consequently results in transfer of heat."
Make sense now?
No?
Ok, think of it like this, in a landslide, there are all sorts of materials being mixed
up and churned up, right?
That's why it's so dangerous.
Well, in these cases of these landslides (both on Mars and on Earth), there are situations
where the rocks on the top layer of the landslide mass or "flow" is lighter, and even unstable
at points.
So, when it gets churned up, it'll go from wherever it is on the bottom, and move to
the top via convection.
Then, the colder rocks will move to the bottom...which will get them hot, and thus get them to the
top.
This kind of "rotation" is not hindered by friction, nor is it required to have ice in
it to do.
In fact, ice would hinder it.
Due to convection, the landslides that are caused by these long ridges with unstable
rocks can just go on and on by using the very basic principles of science:
“Once we had accounted for this mechanical instability – and coupled it with the movement
at phenomenal high speed of the slide – we could show that vortices extending in the
direction of the landslide’s movement were generated, giving rise to the long ridges
that we observe on the surface of the landslide,” Mitchell and Magnarini said in their article
about the landslides.
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6.
Why Couldn't We Figure This Out On Earth?
Now, here is a question you might be pondering, why is it that we needed help from Mars (via
their own landslide issue going on) to figure this out?
After all, we outlined that we had these kinds of landslides on Earth, so why couldn't we
just study them?
Find out the root cause of them from where we are right now?
That would be because of the fact that while these do happen on Earth, the different climates,
gravities, and more lend to the rather destructive nature of the landslides.
To that end, any evidence we could've gotten that would've described how the landslides
did this would've been gone before we could've even gotten there.
But, because of the composition of Mars and its terrain, we're able to view it from afar
and determine certain things that we honestly can't do up close here on Earth.
In fact, it's been noted by many scientists that the "evidence" of these landslides are
able to be left behind for many years, versus minutes or maybe hours here on Earth.
Thus, because we now know the logical explanation behind these types of mudslides, we can prepare
for them here on Earth and save lives: As the pair of authors say in their article,
“The findings are important.
On Earth, the incomplete record of such catastrophic events can lead to misinterpretations and
overlooking of the hazard of these landslides.
But, as they happened in the past, they will happen in the future, posing great risk to
infrastructures and people lives.”
5.
So How Exactly Did They Figure This Out?
W kind of skated over this before, but let's talk about how the teams behind this revolutionary
study were able to figure out the landslide issue.
They had to use some pretty deep technology and processes in order to get things to work:
"To investigate whether there may be other explanations, we made computer models of the
landslide called "digital elevation" models.
These are 3-D representations of terrain, obtained from high-resolution satellite images
and the terrain's elevation data.
From this data, we could calculate the thickness of the landslides, the length of the ridges,
their height and their wavelength—that is the distance from crest to crest between two
ridges next to each other."
Through these models, they were able to figure out things like whether ice was a factor in
the run out landslides, as well as the materials that were comprising the flow, and the ridges
that helped create these massive landslides to begin with:
"We showed that the wavelength of the ridges is constantly two to three times the value
of the thickness of the landslide.
This relationship has previously only been demonstrated in laboratory experiments – which
do not involve ice—and our result is the first field evidence."
This is why science is so impressive at times, because they were able to use these models
and tests and more to figure out the many specific factors that created the landslides.
And who knows what else these scans can reveal about other landslides on Mars and Earth in
the future.
4.
How This Helps Us On Earth and On Mars So let's ask the obvious question, how does
this help us?
How does knowing the origin of these long run-out landslides help us both here on Earth,
as well as on Mars?
Well, in terms of the Earth question, that would be a lot.
Because while these landslides are somewhat rare on Earth, they still happen.
Plus, regular landslides happen on Earth much more than you might expect.
So, if we're able to do things like determine the origins of the rarest of the landslides,
we'll be able to use them to help further understand basic landslides.
Maybe even be able to predict when they will happen, how much damage they will do, etc.
Then, there's the Mars question, and it's important to ask about the Mars situation
because we're aiming to be going there in the next few years.
These kinds of landslides are much more common Mars than they are on Earth, and part of the
reason they were able to figure these things out is because they happen so often on the
red planet.
Thus, if we're going to be living there in the potential near future, we probably should
know more about the dangers we face: "Turning our look further away to understand
what is near us is sometimes a fundamental change of perspective.
But, as we know landslides are also still happening on Mars, these studies will set
the background knowledge for risk mitigation of human settlements on Mars, no matter how
far in the future they are still."
3.
The Colonization Of Mars These landslides bring up a very real problem
that we are aiming to prepare for, the uncertainty of living on Mars.
Granted, we're still working on actually flying and getting to Mars, but then we have to deal
with the various situations that will be required of us to make a colony on the red planet.
Even if it's just for a small group of people in that first mission.
After all, we're already planning for things like the atmospheric re-entry, radiation shielding,
the lack of oxygen, the cold temperatures, and more.
That's a lot to think about right there.
Then, you throw in things like massive landslides, and you're just stacking up the problems right
there.
Being able to know how these massive landslides form though will be a boom in terms of trying
to get things to work in the large scale.
For example, if there is a relatively flat area on Mars where we can land, get water,
not be in danger of exposure AND is miles away from these landslides, that's a perfect
place to try and make a colony.
Versus an area that has the potential for a landslide that could reach a long distance.
True, it's nearly impossible to predict when and how big a landslide will go, but you have
to believe that if we're going to live anywhere on Mars...it's going to be in a place where
we're not likely to get drowned by mud.
I'm just saying.
2.
The Danger Of Mars Plus, to add onto all of that, these landslides
bring forth a very real question, "What else is on Mars that could hurt us that we don't
know about already?"
We've already outlined some of the dangers in the last entry, but tell me, did you know
Mars had landslides before this video?
Because if you didn't, that means a lot of people likely didn't.
We can't watch Mars all the time, not in the way we want to.
We're confined to certain satellites, probes, camera, telescopes, etc.
That's why certain upcoming rover and scouting missions are so important, because if they
were to find something, anything that could pose a potential threat to human life on Mars,
you have to believe that it's going to affect the launch of the colony missions.
For example, there's a probe circling the planet right now looking for trace gasses
that can be found in the atmosphere.
What if it finds something that we didn't expect?
Didn't know about?
Weren't prepared for?
That could change everything.
1.
One Step At A Time If this landslide issue has taught us anything
about the upcoming Mars missions, it's that we really do need to take this one step at
a time.
Because rushing into things will just make it all the more destructive if we're not prepared
for every possible contingency.
Sure, it's impossible to be ready for everything, even with multiple space agencies preparing
for us to get to Mars, but with all those eyes on the red planet, we should be able
to see or detect much of what's there to potentially harm us.
It's almost impossible to know what the next hurdle will be, even if it's something small
that could potentially cause a problem when we land.
Like a shift in the terrain that we didn't encounter before, or something of the like.
The point here is that these models, these scans, these questions about why things happen
on planets like Mars and Earth give us knowledge.
With that knowledge, we take a step forward and help ourselves get ready for what comes
next.
Thanks for watching everyone!
What do you think about these curious landslides and why they happen on Mars and Earth?
Are you glad it's only a freak accident of sorts on our planet?
What other things do you think we'll find in regards to similarities between our two
planets?
Let me know in the comments below, be sure to subscribe, and I'll see you next time on
the channel!