For so long the Red Planet has been something of a symbol of hope for humankind. A far-off target
for our technological ambition, and an alien world that one day we want to explore first hand.
Until such time as we can just jet off in our rockets and take a walk around the place, however,
we’ve been steadily monitoring it from afar. And, just recently, there have been some
seemingly concerning developments. This is Unveiled, and today we’re
answering the extraordinary question; is something terrible happening to Mars?
Do you need the big questions answered? Are you constantly curious? Then why not subscribe to
Unveiled for more clips like this one? And ring the bell for more thought-provoking content!
As the fourth most planet from the sun, the next furthest out from Earth, and with various
attributes that are none too dissimilar to our own planet’s… it’s easy to see why we’ve grown
so interested in Mars over the years. Much more so than with the hellish Venus (closer to the sun
and choking in carbon dioxide) the suggestion has always been that one day humans would visit Mars.
And, ultimately, that one day we could move there permanently, setting up an early off-Earth outpost
as our species seeks to spread out into space. As such, over the years, and especially since the
mid-twentieth century, we’ve been driven to get to know Mars. And, through orbiters and landers,
we’ve gotten a pretty good picture of it. We have a steady stream of images that
have been beamed back by the machines that human ingenuity has placed on its surface…
and, in 2022, we were able to pair those pictures up with reliable sound for a breakthrough moment,
thanks to microphones on NASA’s Perseverance Rover. More than just looking and seeing,
though, we’re also feeling Mars better than ever before. We have an increasing knowledge of its
inner workings and its natural history, one aspect of which involves us measuring for marsquakes.
On Earth, we know that earthquakes are linked to our planet’s tectonic activity; to the movements,
collisions, and frictions of tectonic plates. We’ve mapped all the major fault lines, and we
have a good idea of where the most at-risk regions are. The situation on Mars is a little different,
however. In the past, more often than not, Mars has been described as tectonically inactive.
And, while science no longer sees the situation as quite so black and white, it’s easy to see
why that label has been tagged onto it. While there are parts of the Martian surface that
differ from other parts, there aren’t constantly moving masses of crust as there are on Earth.
There aren’t tectonic plates, and so tectonic activity is limited. Some models of (and theories
on) Martian history suggest that Mars did once have more Earth-like tectonic movements, but it’s
widely accepted that it’s all extremely quiet on that front now. In a figurative sense, the planet
doesn’t quite breathe like our own world does. And yet, in recent years especially,
there have been countless reports of marsquakes - earthquakes on Mars – where the ground below has
rumbled and roared to prove that apparently there is life in the old place still.
And, in May 2022, news broke of a magnitude 5.0 quake event, the largest ever recorded on Mars,
and reason for major interest. Because how can that be? Is something going wrong on
Mars to cause the quakes? And, if so, should we be worried about its future?
The data for that quake (and, indeed, most others) comes from NASA’s InSight lander vehicle.
It was launched in 2018, and is specifically designed to measure Martian seismic activity,
to give us greater knowledge of what happens below the dusty surface. InSight clocked its
first marsquake in 2019 and has now reportedly measured more than 1,300 quakes in total.
It’s expected that the lander will be retired sometime around the end of 2022, though,
so that 5.0 quake it measured in May could well be remembered as the largest it ever caught,
as most of the others are extremely faint. Faint, strong, or middling, though, the question
remains; how are these things happening without tectonic plates to cause them? Well, the fact that
they are happening shows that Mars, actually, isn’t totally tectonically inactive. There’s
volcanism on the Red Planet which, really, science has known about for years. Mars’ upper mantle,
immediately below its crust, does move and shift… and this does generate enough force to make the
ground shake. It’s image as something of a dead world has proven difficult for Mars to shake off,
not least because its atmosphere is also incredibly thin… but the marsquakes powered by
volcanism – by a gradually churning mantle beneath the barren surface – prove that this planet is
more than just silent and lifeless. So, in fact, does that mean that there is cause for concern?
Thankfully, the answer is: not especially. With more than one thousand quakes measured
by just one device, across a timespan of about three years only, it might seem as though Mars
is really having some problems. Whereas before it had been depicted as though it were just a
cold and quiet world, we now know it to be almost constantly moving, shaking, and vibrating from the
inside to out. But the key is that the marsquakes themselves are all still relatively weak. Even the
5.0 magnitude record event ranks low when compared to quakes on Earth. Here, we have hundreds of
earthquakes every year that chart higher than 5.0… and, as for those that chart lower (which
all other marsquakes do) we have hundreds of thousands of them. And so, perhaps the 1,300 or so
on Mars (since 2019) suddenly doesn’t feel quite so many. And they’re certainly not destructive.
In reality, while there has been a seeming sudden rush on reports of marsquakes,
this is more testament to the much-improved technologies that we now have to detect them.
The first attempts to monitor marsquakes were actually made way back in the 1970s,
as part of NASA’s Viking program… but the early seismometers that were attached to the Vikings
struggled to differentiate between potential quakes and everyday wind noise. The InSight
lander is deliberately protected from the Martian winds to avoid this, meaning that we’re now as
confident as we can be that what’s being measured really are marsquakes in action. Other notable
events captured by InSight include a couple of low magnitude 3 quakes reported in April 2021,
and two of magnitudes 4.1 and 4.2 later in the same year. Our catalog of marsquakes is quickly
improving, then, and that’s good news (not bad news) for our ongoing study of the planet.
Armed with this improving knowledge, what are the next steps we should take?
Ultimately, getting a handle on the conditions of Mars below the surface is believed to be
vital if we ever hope to visit or live there. By now, there have been various ideas put forward
toward terraforming the planet into a world that’s more suitable for human habitation…
but any (and all) of them could well be in vain if we fail to properly investigate the Martian
foundations first of all. And that’s what missions like InSight are doing. And, while InSight is
scheduled to go into safe mode over the rest of 2022, before eventually being retired altogether
as a result of dust accumulation on its solar panel wings, this drive to explore the undersides
of alien worlds isn’t expected to let up. In the coming years and decades, it could be
that our attentions turn away from Mars and on to other off-Earth candidates for human travel,
like the much-debated gas giant moons of Europa and Titan. And, when we get to those in earnest,
perhaps we’ll take a similarly deep dive into their inner makeups, before we ever even attempt
to set foot on them ourselves. The inner geology of alien worlds is becoming ever more crucial in
our bid to eventually explore the solar system. So, what’s your verdict on the increasing reports
of unrest on Mars? On the now thousands of marsquakes that have been recorded there?
And on the fact that the strongest has recently breached 5.0 magnitude?
Are you concerned for the planet, or simply excited by the new data that’s available?
At first reading, it might feel like our solar system neighbor is enduring
some unusually rough conditions… but, really, what’s happening now is nothing new for Mars.
What is new is our ability to track those conditions, and our realization that Mars perhaps
isn’t quite as inactive as we’ve traditionally painted it to be. Something’s happening up there,
and we’re only just cottoning onto it. And so, from another perspective, these low level
marsquakes might actually signify hope that Mars might yet be suitable for adaptation…
and for a human species that requires its home planet never to stand still.
What do you think? Is there anything we missed? Let us know in the comments, check out these other
clips from Unveiled, and make sure you subscribe and ring the bell for our latest content.