During late summer in the Southern hemisphere on Mars, the angle of the sunlight as it strikes the surface brings out some subtle details on the planet’s surface.
In this image, the HiRISE camera on board NASA’s Mars Reconnaissance Orbiter (MRO) captured an area of frozen carbon dioxide on the surface. Some of the carbon dioxide ice has melted, giving it a swiss-cheese appearance. But there is also an unusual hole or crater on the right side of the image, with some of the carbon dioxide ice clearly visible in the bottom of the pit.
NASA scientists are uncertain what exactly caused the unusual pit. It could be an impact crater, or it could be a collapsed pit caused by melting or sublimation of sub-surface carbon dioxide ice.
MRO has been in orbit around Mars for over 10 years, and has completed over 50,000 orbits. The MRO has two cameras. The CTX camera is lower resolution, and has imaged over 99% of the Martian surface. HiRISE is the high-resolution camera that is used to closely examine areas and objects of interest, like the unusual surface pit in this image.
By day, Kevin Gill is a software engineer at the Jet Propulsion Laboratory. But on nights and weekends he takes data from spacecraft and turns them into scenes that can transport you directly to the surface of Mars.
Gill is one of many so-called “amateur” image editing enthusiasts that take real, high-resolution data from spacecraft and create views that can make you feel like you are standing on the surface of Mars, or out flying around the Solar System.
Some of the best data around for these purposes come from the HiRISE camera on board the Mars Reconnaissance Orbiter. Data known as Digital Terrain Model (DTM) files, the HiRISE DTMs are made from two or more images of the same area of a region on Mars, taken from different angles. This data isn’t just for making stunning images or amazing movies. For scientists, DTMs are very powerful research tools, used to take measurements such a elevation information and model geological processes.
So, just how do you go from this DTM image from HiRISE:
To this amazing image?
I’m going to let Kevin explain it:
To prep the data, I use Photoshop (to convert the JP2 file to a TIFF), and then standard GIS tools like gdal (Geospatial Data Abstraction Library) to create textures for 3D modeling. Using Autodesk Maya, I input those into a material as a color texture (orthoimagery) or displacement map (the DTM data).
I connect that material to a NURBS plane (sort of like a polygon mesh) that is scaled similarly to the physical properties of the data. I set up a camera at a nice angle (it takes a number of low-resolution test renders to get an angle I like) and let it render.
Then I just pull that render into Photoshop where I have a series of monochromatic color tints which gives the image it’s Martian feel. For the sky, I use either a sky from a MSL MastCam image or one that I took outside with my cell phone. If I’m using a sky I took with my cell phone, I’ll adjust the colors to make it look more like it would on Mars. If the colors in the image are still boring at this point, I may run a HDR adjustment on it in Photoshop.
What all this means is that you can create all these amazing view, plus incredible flyover videos, like this one Kevin put together of Endeavour Crater:
Or you can have some fun and visualize where the Curiosity rover is sitting:
We’ve written about this type of image editing previously, with the work of the people at UnmannedSpaceflight.com and others. Of course, the image editing software keeps improving, along with all the techniques.
Kevin also wanted to point out the work of other image editing enthusiast, Sean Doran.
“Sean’s work is resulting in views similar to mine,” Kevin said via email. “I know he’s using a process very different from mine, but we are thinking along the same lines in what we want out of the end product. His are quite impressive.”
For example, here is a flyover video of the Opportunity rover sitting along the rim of Endeavour Crater:
Viewing orbital images of the rovers as they go about their business on the surface of Mars is pretty cool. Besides being of great interest to anyone keen on space in general, they have scientific value as well. New images from the High Resolution Imaging Science Equipment (HiRise) camera aboard the Mars Reconnaissance Orbiter (MRO) help scientists in a number of ways.
Recent images from HiRise show the Mars Science Laboratory (MSL) Curiosity on a feature called the Naukluft Plateau. The Plateau is named after a mountain range in Namibia, and is the site of Curiosity’s 10th and 11th drill targets.
Orbital imagery of the rovers is used to track the activity of sand dunes in the areas the rovers are working in. In this case, the dune field is called the Bagnold Dunes. HiRise imagery allows a detailed look at how dunes change over time, and how any tracks left by the rover are filled in with sand over time. Knowledge of this type of activity is a piece of the puzzle in understanding the Martian surface.
But the ability to take such detailed images of the Martian surface has other benefits, as well. Especially as we get nearer to a human presence on Mars.
Orbital imaging is turning exploration on its ear. Throughout human history, exploration required explorers travelling by land and sea to reconnoiter an area, and to draw maps and charts later. We literally had no idea what was around the corner, over the mountain, or across the sea until someone went there. There was no way to choose a location for a settlement until we had walked the ground.
From the serious (SpaceX, NASA) to the fanciful (MarsOne), a human mission to Mars, and an eventual established presence on Mars, is a coming fact. The how and the where are all connected in this venture, and orbital images will be a huge part of choosing where.
Tracking the changes in dunes over time will help inform the choice for human landing sites on Mars. The types and density of sand particles may be determined by monitoring rover tracks as they fill with sand. This may be invaluable information when it comes to designing the types of facilities used on Mars. Critical infrastructure in the form of greenhouses or solar arrays will need to be placed very carefully.
Sci-Fi writers have exaggerated the strength of sand storms on Mars to great effect, but they are real. We know from orbital monitoring, and from rovers, that Martian sandstorms can be very powerful phenomena. Of course, a 100 km/h wind on Earth is much more dangerous than on Mars because of the density of the atmosphere. Martian air is 1% the density of Earth’s, so on Mars the 100 km/h wind wouldn’t do much.
But it can pick up dust, and that dust can foul important equipment. With all this in mind, we can see how these orbital images give us an important understanding of how sand behaves on Mars.
There’s an unpredictability factor to all this too. We can’t always know in advance how important or valuable orbital imagery will be in the future. That’s part of doing science.
But back to the cool factor.
For the rest of us, who aren’t scientists, it’s just plain cool to be able to watch the rovers from above.
Scene from ‘The Martian’ starring Matt Damon as NASA astronaut Mark Watney contemplating magnificent panoramic vista while stranded alone on Mars.
Credits: 20th Century Fox
See real Martian maps and flyover video from DLR and NSA below
Go now and experience Hollywood’s blockbuster new space epic ‘The Martian’ helmed by world renowned director Ridley Scott and starring Matt Damon as the protagonist, NASA astronaut Mark Watney. And you can follow Watney’s dramatic fictional path across the Red Planet in newly released real photos and a flyover video of the region, from DLR and NASA, as it looks today.
‘The Martian’ is a mesmerizingly enjoyable cinematic triumph for everyone that’s all about science, space exploration and one man’s struggle to survive while left totally isolated on the Red Planet in the face of seemingly insurmountable odds – relying on his wits alone to endure “on a planet where nothing grows” while hoping somehow for a rescue by NASA four years in the future.
The movie combines compelling and plausible storytelling with outstanding special effects that’s clearly delighting huge audiences worldwide with a positive and uplifting view of what could be achieved in the future – if only we really put our minds to it!
Based on the bestselling book by Andy Weir, ‘The Martian’ movie from 20th Century Fox tells the spellbinding story of how NASA astronaut Mark Watney is accidentally stranded on the surface of Mars during the future Ares 3 manned expedition in 2035, after a sudden and unexpectedly fierce dust storm forces the rest of the six person crew – commanded by Jessica Chastain as Commander Lewis – to quickly evacuate after they believe he is dead.
Now you can follow the fictional exploits of Mark Watney’s stunningly beautiful trail across the real Mars through a set of newly released maps, imagery and a 3D video created by the DLR, the German Aerospace Agency, and NASA – and based on photos taken by the European Space Agency’s Mars Express orbiter and NASA’s Mars Reconnaissance Orbiter (MRO).
DLR’s stunning 3D overflight video sequence was created from a dataset of 7300 stereo images covering roughly two-and-a-half million square kilometres of precisely mapped Martian landscape captured over the past 12 years by Mars Express High Resolution Stereo Camera (HRSC). The electric score is by Stephan Elgner.
Video Caption: Following the path of The Martian – video generated using images acquired by the Mars Express orbiter. Scientists from German Aerospace Center, DLR– who specialise in producing highly accurate topographical maps of Mars – reconstructed Watney’s route using stereo image data acquired by the High Resolution Stereo Camera on board European Space Agency’s #MarsExpress spacecraft. They then compiled this data into a video that shows the spectacular landscape that the protagonist would see ‘in the future’ on his trek from Ares 3 at Acidalia Planitia/Chryse Planitia to Ares 4 at Schiaparelli Crater. Credit: DLR/ESA
Ridley Scotts ‘The Martian’ takes place mostly on the surface of the Red Planet and is chock full of breathtakingly beautiful panoramic vistas. In the book you can only imagine Mars. In the movie Scott’s talents shine as he immerses you in all the action on the alien world of Mars from the opening scene.
Starting with the landing site for Watney’s Ares 3 mission crew at Acidalia Planitia, the book and movie follows his triumphs and tribulations, failures and successes as he logically solves one challenging problem after another – only to face increasingly daunting and unexpected hurdles as time goes by and supplies run low.
The DLR route map shows a real topographic view of Watney’s initial journey back and forth from the fictional Ares 3 landing site to the actual landing site of NASA’s 1997 Mars Pathfinder lander and Sojourner rover mission at the mouth of Ares Vallis.
The map continues with Watney’s months-long epic trek to the fictional landing site of Ares 4 Mars Ascent Vehicle (MAV) spacecraft at Schiaparelli Crater, by way of Marth Valles and other Martian landmarks, craters and valleys.
At the request of Andy Weir, the HiRISE camera on NASA’s MRO orbiter took photos of the Martian plain at the Ares 3 landing site in Acidalia Planitia, which is within driving distance from the Pathfinder lander and Sojourner rover in the book and movie.
The Martian is all about how Watney uses his botany, chemistry and engineering skills to “Science the sh** out of it” to grow food and survive until the hoped for NASA rescue.
Learning how to live off the land will be a key hurdle towards enabling NASA’s real strategy for long term space voyages on a ‘Journey to Mars’ and back.
‘The Martian’ is a must see movie that broadly appeals to space enthusiasts and general audiences alike who can easily identify with Watney’s ingenuity and will to live.
Since its worldwide premiere on Oct. 2, ‘The Martian’ has skyrocketed to the top of the US box office for the second weekend in a row, hauling in some $37.3 million. The total domestic box office receipts now top $108 million and rockets to over $228 million worldwide in the first 10 days alone.
I absolutely loved ‘The Martian’ when I first saw the movie on opening weekend. And enjoyed it even more the second time, when I could pick up a few details I missed the first time around.
The movie begins as the crew evacuates after they believe Watney was killed by the dust storm. Watney actually survived the storm but lost contact with NASA. The film recounts his ingenious years long struggle to survive, figure out how to tell NASA he is alive and send a rescue crew before he starves to death on a planet where nothing grows. Watney’s predicament is a survival lesson to all including NASA.
‘The Martian’ was written by Andy Weir in 2010 and the film could well break the October movie box office record currently held by ‘Gravity.’
The movie closely follows the book, which I highly recommend you read at some point.
By necessity, the 2 hour 20 minute movie cannot capture every event in the book. So there is an abbreviated sense of Watney’s detailed science to survive and lengthy overland trips.
All the heroics and difficulties in traveling to Pathfinder and back and getting communications started, as well as the final month’s long journey to Schiaparelli crater are significantly condensed, but captured in spirit.
The Martian is brilliant and intelligent and rivals Stanley Kubrik’s space epic ‘2001: A Space Odyssey’ as one of the top movies about humanities space exploration quest.
The one big science inaccuracy takes place right at the start with the violent Martian dust storm.
On Mars the atmosphere is so thin that the winds would not be anywhere near as powerful or destructive as portrayed. This is acknowledged by Weir and done for dramatic license. We can look past that since the remainder of the tale portrays a rather realistic architectural path to Mars and vision of how scientists and engineers think. Plus the dust storms can in fact kick up tremendous amounts of particles that significantly block sunlight from impinging on solar energy generating panels.
Personally I can’t wait for the ‘Directors Cut’ with an added 30 to 60 minutes of scenes that were clearly filmed – but not included in the original theatrical release.
THE MARTIAN features a star studded cast that includes Matt Damon, Jessica Chastain, Kristen Wiig, Kate Mara, Michael Pena, Jeff Daniels, Chiwetel Ejiofor, and Donald Glover.
“NASA has endorsed “The Martian’” Jim Green, NASA’s Director of Planetary Sciences, told Universe Today. Green served as technical consultant on the film.
The DLR film was created by a team led by Ralf Jaumann from the DLR Institute of Planetary Research, Principal Investigator for HRSC. He believes that producing the overflight video was not just a gimmick for a science fiction film:
“Mars generates immense fascination, and our curiosity continues to grow! Many people are interested in our research, and young people in particular want to know what it is really like up there, and how realistic the idea that one day people will leave their footprints on the surface of Mars truly is. The data acquired by HRSC shows Mars with a clarity and detail unmatched by any other experiment. Only images acquired directly on the surface, for instance by rovers like Curiosity, are even closer to reality, but they can only show a small part of the planet. Thanks to this animation, we have even noticed a few new details that we had not seen in a larger spatial context. That is why we made the film – it helps everyone see what it would be like for Watney to travel through these areas… the clouds were the only creative touches we added, because, fortunately, they do not appear in the HRSC data,” according to a DLR statement.
Here’s the second official trailer for The Martian:
As a scientist and just plain Earthling, my most fervent hope is that ‘The Martian’ will inspire our young people to get interested in all fields of science, math and engineering and get motivated to become the next generation of explorers – here on Earth and beyond to the High Frontier to benefit all Mankind.
Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.
As the midsummer Sun beats down on the southern mountains of Mars, bringing daytime temperatures soaring up to a balmy 25ºC (77ºF), some of their slopes become darkened with long, rusty stains that may be the result of water seeping out from just below the surface.
The image above, captured by the HiRISE camera aboard NASA’s Mars Reconnaissance Orbiter on Feb. 20, shows mountain peaks within the 150-km (93-mile) -wide Hale Crater. Made from data acquired in visible and near infrared wavelengths the long stains are very evident, running down steep slopes below the rocky cliffs.
These dark lines, called recurring slope lineae (RSL) by planetary scientists, are some of the best visual evidence we have of liquid water existing on Mars today – although if RSL are the result of water it’s nothing you’d want to fill your astro-canteen with; based on the first appearances of these features in early Martian spring any water responsible for them would have to be extremely high in salt content.
According to HiRISE Principal Investigator Alfred McEwen “[t]he RSL in Hale have an unusually “reddish” color compared to most RSL, perhaps due to oxidized iron compounds, like rust.”
See a full image scan of the region here, and watch an animation of RSL evolution (in another location) over the course of a Martian season here.
Hale Crater itself is likely no stranger to liquid water. Its geology strongly suggests the presence of water at the time of its formation at least 3.5 billion years ago in the form of subsurface ice (with more potentially supplied by its cosmic progenitor) that was melted en masse at the time of impact. Today carved channels and gullies branch within and around the Hale region, evidence of enormous amounts of water that must have flowed from the site after the crater was created. (Source.)
The crater is named after George Ellery Hale, an astronomer from Chicago who determined in 1908 that sunspots are the result of magnetic activity.
UPDATE April 13: Conditions for subsurface salt water (i.e., brine) have also been found to exist in Gale Crater based on data acquired by the Curiosity rover. Gale was not thought to be in a location conducive to brine formation, but if it is then it would further strengthen the case for such salt water deposits in places where RSL have been observed. Read more here.
What is up with the fossils on Mars? Found – a dinosaur skull on Mars? Discovered – a rat, squirrel or gerbil on Mars? In background of images from Curiosity, vertebrae from some extinct Martian species? And the human skull, half buried in photos from Opportunity Rover. All the images are made of stone from the ancient past and this is also what is called Pareidolia. They are figments of our imaginations, and driven by our interest to be there – on Mars – and to know that we are not alone. Altogether, they make a multitude of web pages and threads across the internet.
Rock-hounds and Martian paleontologists, if only amateur or retired, have found a bounty of fascinating rocks nestled among the rocks on Mars. There are impressive web sites dedicated to each’s eureka moment, dissemination among enthusiasts and presentation for discussion.
Be sure to explore, through the hyperlinks, many NASA, NASA affiliates’ and third party websites – embedded throughout this article. Also, links to specific websites are listed at the end of the article.
The centerpiece of recent interest is the dinosaur skull protruding from the Martian regolith, teeth still embedded, sparkling efferdent white. There are no sockets for these teeth. Dinosaur dentures gave this senior citizen a few extra good years. The jaw line of the skull has no joint or connection point with the skull. So our minds make up the deficits, fill in the blanks and we agree with others and convince ourselves that this is a fossilized skull. Who knows how this animal could have evolved differently.
But evolve it did – within our minds. Referencing online dictionaries [ref], “Pareidolia is the imagined perception of a pattern (or meaning) where it does not actually exist, as in considering the moon to have human features.” I must admit that I do not seek out these “discoveries” on Mars but I enjoy looking at them and there are many scientists at JPL that have the same bent. Mars never fails to deliver and caters to everyone, but when skulls and fossils are seen, it is actually us catering to the everyday images and wishes we hold in our minds.
The “Rat on Mars” (main figure, top center) is actually quite anatomically complete and hunkered down, having taken its final gasps of air, eons ago, as some cataclysmic event tore the final vestiges of Earth-like atmosphere off the surface. It died where it once roamed and foraged for … nuts and berries? Surprisingly, no nuts have been found. Blueberries – yes – they are plentiful on Mars and could have been an excellent nutritional source for rats; high in iron and possibly like their Earthly counterpart, high in anti-oxidants.
The blueberries were popularized by Dr. Steve Squyres, the project scientist of the Mars Exploration Rover (MER) mission. Discovered in Eagle crater and across Meridiani Planum, “Blueberries” are spherules of concretions of iron rich minerals from water. It is a prime chapter in the follow-the-water story of Mars. And not far from the definition of Pareidolia, Eagle Crater refers to the incredible set of landing bounces that sent “Oppy” inside its capsule, surrounded by airbags on a hole-in-one landing into that little crater.
Next, is the face of Mars of the Cydonia region (Images of Cydonia, Mars, NSSDC). As seen in the morphed images, above, the lower resolution Viking orbiter images presented Mars-o-philes clear evidence of a lost civilization. Then, Washington handed NASA several years of scant funding for planetary science, and not until Mars Global Surveyor, was the Face of Cydonia photographed again. The Mars Orbiter Camera from the University of Arizona delivered high resolution images that dismissed the notion of a mountain-sized carving. Nonetheless, this region of Mars is truly fascinating geologically and does not disappoint those in search of past civilizations.
And long before the face on Mars in Cydonia, there were the canals of Mars. Spotted by the Mars observer Schiaparelli, the astronomer described them as “channels” in his native language of Italian. The translation of the word turned to “Canals” in English which led the World to imagine that an advanced civilization existed on Mars. Imagine if you can for a moment, this world without Internet or TV or radio and even seldom a newspaper to read. When news arrived, people took it verbatim. Canals, civilizations – imagine how imaginations could run with this and all that actually came from it. It turns out that the canals or channels of Mars as seen with the naked eye were optical illusions and a form of Pareidolia.
So, as our imagery from Mars continues to return in ever greater detail and depth, scenes of pareidolia will fall to reason and we are left with understanding. It might seem sterile and clinical but its not. We can continue to enjoy these fascinating rocks – dinosaurs, rats, skulls, human figures – just as we enjoy a good episode of Saturday Night Live. And neither the science or the pareidolia should rob us of our ability to see the shear beauty of Mars, the fourth rock from the Sun.
In the article’s main image, what should not be included is the conglomerate rock on Mars. NASA/JPL scientists and geologists quickly recognized this as another remnant of Martian hydrologics – the flow of water and specifically, the bottom of a stream bed (NASA Rover Finds Old Streambed on Martian Surface). Truly a remarkable discovery and so similar to conglomerate rocks on Earth.
In March 2012, amateur astronomers began observing unusual clouds or plumes along the western limb of the red planet Mars. The plumes, in the southern hemisphere rose to over 200 kilometers altitude persisting for several days and then reappeared weeks later.
So a group of astronomers from Spain, the Netherlands, France, UK and USA have now reported their analysis of the phenomena. Their conclusions are inconclusive but they present two possible explanations.
Mars and mystery are synonymous. Among Martian mysteries, this one has persisted for three years. Our own planet, much more dynamic than Mars, continues to raise new questions and mysteries but Mars is a frozen desert. Frozen in time are features unchanged for billions of years.
In March 2012, the news of the observations caught the attention of Universe Today contributing writer Bob King. Reported on his March 22nd 2012 AstroBob blog page, the plumes or clouds were clear to see. The amateur observer, Wayne Jaeschke used his 14 inch telescope to capture still images which he stitched together into an animation to show the dynamics of the phenomena.
Now on February 16 of this year, a team of researchers led by Agustín Sánchez-Lavega of the University of the Basque Country in Bilbao, Spain, published their analysis in the journal Nature of the numerous observations, presenting two possible explanations. Their work is entitled: “An Extremely high-altitude plume seen at Mars morning terminator.”
The phenomena occurred over the Terra Cimmeria region centered at 45 degree south latitude. This area includes the tiger stripe array of magnetic fields emanating from concentrations of ferrous (iron) ore deposits on Mars; discovered by the Mars Global Surveyor magnetometer during low altitude aerobraking maneuvers at the beginning of the mission in 1998. Auroral events have been observed over this area from the interaction of the Martian magnetic field with streams of energetic particles streaming from the Sun. Sánchez-Lavega states that if these plumes are auroras, they would have to be over 1000 times brighter than those observed over the Earth.
The researchers also state that another problem with this scenario is the altitude. Auroras over Mars in this region have been observed up to 130 km, only half the height of the features. In the Earth’s field, aurora are confined to ionospheric altitudes – 100 km (60 miles). The Martian atmosphere at 200 km is exceedingly tenuous and the production of persistent and very bright aurora at such an altitude seems highly improbable.
The duration of the plumes – March 12th to 23rd, eleven days (after which observations of the area ended) and April 6th to 16th – is also a problem for this explanation. Auroral arcs on Earth are capable of persisting for hours. The Earth’s magnetic field functions like a capacitor storing charged particles from the Sun and some of these particles are discharged and produced the auroral oval and arcs. Over Mars, there is no equivalent capacitive storage of particles. Auroras over Mars are “WYSIWYG” – what you see is what you get – directly from the Sun. Concentrated solar high energy streams persisting for this long are unheard of.
The second explanation assessed by the astronomers is dust or ice crystals lofted to this high altitude. Again the altitude is the big issue. Martian dust storms will routinely lift dust to 60 km, still only one-third the height of the plumes. Martian dust devils will lift particles to 20 km. However, it is this second explanation involving ice crystals – Carbon Dioxide and Water – that the researchers give the most credence. In either instance, the particles must be concentrated and their reflectivity must account for the total brightness of the plumes. Ice crystals would be more easily transported to these heights, and also would be most highly reflective.
The paper also considered the shape of the plumes. The remarkable quality of modern amateur astrophotography cannot be overemphasized. Also the duration of the plumes was considered. By local noon and thereafter they were not observed. Again, the capabilities tendered by ground-based observations were unique and could not be duplicated by the present set of instruments orbiting Mars.
Still too many questions remain and the researchers state that “both explanations defy our present understanding of the Mars’ upper atmosphere.” By March 20th and 21st, the researchers summarized that at least 18 amateur astronomers observed the plume using from 20 to 40 cm telescopes (8 to 16 inch diameter) at wavelengths from blue to red. At Mars, the Mars Color Imager on MRO (MARCI) could not detect the event due to the 2 hour periodic scans that are compiled to make global images.
Of the many ground observations, the researchers utilized two sets from the venerable astrophotographers Don Parker and Daiman Peach. While observations and measurements were limited, the researchers analysis was exhaustive and included modeling assuming CO2, Water and dust particles. The researchers did find a Hubble observation from 1997 that compared favorably with the 2012 events and likewise modeled that event for comparison. However, Hubble results provided a single observation and the height estimate could not be narrowly constrained.
Explanation of these events in 2012 are left open-ended by the research paper. Additional observations are clearly necessary. With increased interest from amateurs and continued quality improvements plus the addition of the Maven spacecraft suite of instruments plus India’s Mars Orbiter mission, observations will eventually be gained and a Martian mystery solved to make way for yet another.
Yesterday, we posted an image taken by the HiRISE camera on the Mars Reconnaissance Orbiter (MRO) of an unusual crater formed by a triple-asteroid. We noticed some comments on the article and on social media of people who said, “hey, that looks like a mountain, not a crater!”
Thanks to our brains, this is a common illusion! Depending on the angle of the Sun when the picture was taken, images of craters taken from overhead (i.e. from orbit) may appear to be a mountain. Here on Earth, we’re used to seeing sunlight coming from overhead, and our brain interprets what we see with the assumption that the sunlight *must* always come from above. Satellite photos of terrain, however usually only show shadows when the light source is nearly horizontal with the surface.
There’s an easy fix for this illusion: flip the image over so it appears the sunlight is coming from above. We’ve done that for you, below:
When a crater is illuminated from above, the shadow inside the crater is near the top and the bright part is near the bottom. A mountain shows exactly the opposite lighting pattern: bright at the top and shadowed at the bottom. This is because the part of the crater or mountain that is most perpendicular to the incoming light reflects it the best. Anyway, your brain interprets pictures under the assumption that the light is from the top of the scene. So if a picture shows an object that is bright at the top and dark at the bottom, it interprets it as a mound lit from above, not as a crater lit from below.
We do know that any photo of anything that is concave or convex will flip in its appearance if the photo is turned upside down. Take a look at any of these crater images from HiRISE, and you’ll likely be deceived on most of them! (remember, they are ALL craters!)
At first glance, you many not guess that this feature on Mars is an impact crater. The reason it looks so unusual is that it likely is a triple impact crater, formed when three asteroids struck all at once in the Elysium Planitia region.
Why do planetary scientists think the three craters did not form independently at different times?
“The ejecta blanket appears to be uniform around the triple-crater showing no signs of burial or overlapping ejecta from overprinting craters,” write scientists Eric Pilles, Livio Tornabene, Ryan Hopkins, and Kayle Hansen on the HiRISE website. “The crater rims are significantly stunted where the craters overlap.”
This oblong-shaped crater could have been created from a triple asteroid, or it could have been a binary asteroid, and one broke apart, creating the three overlapping craters. The team says the two larger craters must have been produced by asteroids of approximately the same size, probably on the order of a few hundred meters across.
“The northern crater might have been created by a smaller asteroid, which was orbiting the larger binary pair, or when one of the binary asteroids broke up upon entering the atmosphere,” the team explained. “The shape of the triple-crater is oblong, suggesting an oblique impact; therefore, another alternative would be that the asteroid split upon impact and ricocheted across the surface, creating additional craters.”
Studying craters on Mars — and there are lots of them, thanks to Mars’ sparse atmosphere — can help estimate the ages of different terrains, as well as revealing materials such as ice or minerals that get exposed from the impact.
Here’s the awesome thing about space and social media: in some cases, you can often follow along with a mission almost as soon as the images come to Earth. A group of Canadians is taking that to the next level this month as they take control of the 211th imaging cycle of a powerful camera on the Mars Reconnaissance Orbiter.
While some images need to be kept back for science investigations, the team is sharing several pictures a day on Twitter and on Facebook portraying the views they saw coming back from the High Resolution Imaging Science Experiment (HiRISE) camera. The results are astounding, as you can see in the images below.
“It’s mind-blowing to realize that when the team, myself included, first look at the images, we are likely the first people on Earth to lay eyes upon a portion of the Martian surface that may have not been imaged before at such high resolution,” stated research lead Livio Tornabene, who is part of Western University’s center for planetary science and exploration.
The team will capture up to 150 images between Nov. 30 and Dec. 12, and already have released close to two dozen to the public. Some of the best are below.