What is that doorway on Mars? Take a look at this image. What do you see?
I'm pretty sure you would say – this is a doorway built into hillsides, just like
one of the other thousand ones that ancient people built on Earth. But the problem is...this
image was taken on Mars. The image was made available by NASA and taken
by the Mast Camera onboard NASA's Mars rover Curiosity on Sol 3466, May 7, 2022.
The Mastcam is the name of the mast-mounted camera system that is equipped with a zoom
function on the Curiosity rover. Mastcam has cameras that can zoom in, focus, and take
pictures and video at high speed to allow detailed examination of distant objects.
So, this last generation device is showing us what clearly looks like an entrance, but
is there a doorway on Mars? The short answer is: no, there's no doorway
on Mars. The elaborate answer is: it is complicated.
Let's try to understand what's happening. =======================================================
So Perseverance is doing its job on the Red Planet, and it is continuously sending data
back to Earth. All the information we are getting is traveling from Mars to Earth: a
nice trip into the solar system. One of the most important pieces of information
comes from the fantastic camera mounted on the rover. This camera is the Mastcam, and
it is located on the rover mast at the eye level of a 2 meters tall person. The technology
used to build this camera is out of this world, I mean, out of Mars, because it was conceived
and constructed on Earth. The camera takes pictures and it can send approximately 148
megabits per sol – as the martian day is called.
With the help of this amazing instrument, we can zoom in on rocks, picking out some
that might preserve signs of past life; we can also understand the terrain around the
rover, looking for some soil textures that could help show if Mars could have supported
tiny forms of life. But another thing we can do is...taking pictures
of sidehills and ask ourselves the question: is that a doorway?
This is what happened recently. Some wondered if that doorway was a piece
of evidence that the red planet could be, or have been, inhabited by aliens.
The “door” was imaged by the rover on the slopes of Mount Sharp, the central massif
within Gale crater, where it landed in 2012. At first sight, this door looks like a “pharaonic
tomb door”, because of its resemblance to some ancient Egyptian remains, and it is only
about one foot high. This is one first hint suggesting that's not
a door. If we take a look at the individual frame where it occurs, we see that this door
is actually really small. Moreover, if we boost the contrast in the dark parts of the
image, you can clearly see a solid rock face at the back of the shadowed interior. So,
even if an alien built this door, it must have been a quite small alien, and also quite
stupid. Why would it build a door that doesn't lead anywhere?
So this doesn't seem to be an alien construction, and we can say that with a high level of confidence
because there are some plausible geological explanations for the presence of this door-looking
feature on Mars. However, we know that reasonable explanations won't deter the conspiracy theorists who
say the doorway really is evidence of life on Mars, and maintain that scientists are
engaged in some sort of cover-up. But think about it: if they were trying to
do a cover-up, they wouldn't be releasing the photos! So a conspiracy doesn't seem very
likely. But there's also a lesson here for serious
searchers for alien life. As astronomer Carl Sagan said, extraordinary claims require
extraordinary evidence. Following this maxim, scientists seeking evidence
of extra-terrestrial life demand much stronger evidence, than, say, someone looking for a
geological formation. And despite decades of searching for evidence of life on Mars,
we have found nothing. It is still possible there may once have been
life on Mars. We may yet find some fossilized relics of ancient cellular life. But suddenly
finding an artifact such as a doorway seems unlikely.
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So what's this door? How was it formed? We said there might be some logical – and
in fact, geological – explanations for this feature to be present on Mars. If you asked
someone with even a little geological experience, I'm sure they will hardly mistake the feature
as a door. So let's try to get into the mind of a geologist
and see what his thought process could look like.
First of all, they would note the thin and repeated layers of sandstone making up the
whole of the rock face, and they would probably think that they were the signature of eroded
remains of hardened sand and dunes. This is all to be re-conducted to the Geology
of Mars. And we know that, a long time ago, these dunes
covered the stream and lake sediments that Curiosity examined earlier in its gradual
climb up through the layers of sedimentary rock making up Mount Sharp.
A geologist would probably be able to spot the steep and fairly straight cracks running
up the rock face. These peculiar features, in geology, are dubbed
“joints”. In a nutshell, joints are fractures that typically
open up when the weight of overlying rock layers is removed by erosion. You must be
careful with them because if you found yourself close to such a rock with joints, it could
be falling onto you. Some geologists suppose that the rock piece we see just in front of
the door, lying on the ground, is indeed one piece of the original rock that cracked up
and fell down: even if we are on another planet, gravity is still present!
One of the visible joints is on the left of the “door” image, but several others can
be made out – including one that forms the smooth wall that lines up with the left side
of the “door” itself. There’s another joint that forms the right side of the feature.
From a more general perspective, we can understand that the whole hillside has been eroded back.
Mars has a complex geological history, and what we are looking at is basically the result
of geological processes that took place during the course of the planet's life.
Maybe the rock cracked up recently, or maybe it happened in the past: by studying the sand
and dust around the hillside, and adopting some models to describe the geological processes
acting on Mars, scientists could be able to tell when the door formed.
From what we know, and from what we can understand, then, the doorway is simply a place where
the wind has been able to scour out the poorly consolidated sand and dust from the rock face
a little more effectively, in an area bounded by the joints on either side.
The base of an overlying bed of sandstone is the “door lintel”, and the sloping
top of a bed of sandstone forms the gentle ramp that leads up to the door.
Artifacts on Mars Anyway, this is not the first time humans
seem to find something unusual in the pictures coming from rovers or probes.
For example, someone claimed that there might be mushrooms on Mars, looking at pictures
sent from NASA's Mars Exploration Rover Opportunity.
Instead, we discovered, sometime later, that they were just “haematite concretions”,
small sphere-shaped pieces of the mineral haematite, even if how they originated is
still a matter of debate between scientists.
This picture:
is also another famous example of how we see the familiar even when it isn't there.
In 1976, Viking Orbiter photographed this feature on the surface of Mars, and some people
said it resembled a human face. The mystery was finally solved in 1998 when Mars global
Surveyor orbiter took the picture on the right. As you can see, with an improved resolution,
we are able to disentangle reality from fantasy.
However, this phenomenon of seeing something that really isn't there is called pareidolia,
and it is not an external phenomenon, but it comes directly from our brain.
Pareidolia is what happens when you see faces in the random pattern of a wallpaper, or when
you see clouds whose form resembles the ones of dogs or humans, or maybe even angels and
unearthly stuff.
For example, and this is really funny, take a look at this image of Jupiter: it looks
really angry, doesn't it?
So, as you can see, seemingly mysterious objects are not only found on Mars.
For example, in December 2021, China’s Chang'e 4 rover spotted a “hut-shaped” object
80 meters away. It duly trundled towards it and revealed it
to be just a boulder, presumably ejected from a nearby impact crater. Don't you think it
looks like a rabbit?
Oh, anyway Chang'e 4 rover is still doing a great job on the lunar surface. The next
Chinese mission was called Chang'e 5. This robotic mission landed on December 1, 2020,
with the goal of collecting rock and dust samples to return to Earth.
We made a video about Chang'e 5 some time ago, why don't you check it out?
Before ending this video, we would recall one of the most famous, and largest, examples
of pareidolia.
This is the Horsehead Nebula. And we know for sure it is not a horse, and it cannot
be an object built by some weird aliens...because...it is simply a vast cosmic cloud of gas and dust.
Scientists from all over the world studied the horsehead nebula, and they found it is
a gas-forming region. It is located in the constellation of Orion,
which is prominent in the winter evening sky in the Northern Hemisphere and the summer
evening sky in the Southern Hemisphere. Colour images reveal a deep-red color that
originates from ionized hydrogen gas predominantly behind the nebula and is caused by the nearby
bright star Sigma Orionis. Heavy concentrations of dust in the Horsehead
Nebula region and neighboring Orion Nebula are localized into interstellar clouds, resulting
in alternating sections of nearly complete opacity and transparency.
The darkness of the Horsehead is caused mostly by thick dust blocking the light of stars
behind it, while bright spots in the Nebula's base are young stars just in the process of
forming. However, it looks like a horse only if you
collect the image data in a filter sensitive to the right part of the electromagnetic spectrum.
If we shift wavelengths, by simply looking at the nebule in some other filters, the recognizable
shape will surprisingly vanish!
Thanks for watching everyone! What do you guys think about this video? Did
you know about the pareidolia phenomenon? Let me know in the comments below, be sure
to subscribe, and I'll see you next time on the channel!