Humans love a good space story. That's why it's so much fun to speculate about unusual objects seen in images of Mars. Our imaginations turn rock formations into fish and cosmic rays into alien communications. A recent image from the NASA Perseverance rover generated plenty of jokes about what looks like a rear end. Is it an alien keister? Nope. It's just a goofy rock formation.
Join us as we explore some famous Mars mysteries and the scientific explanations behind them.
NASA's Viking 1 Orbiter zipped near Mars in 1976 and took this now iconic image of the surface. What got everyone excited is the face-like formation in the upper center of the picture. If you have a creative mind, it's easy to see it as having two eyes, a nose, a mouth and a weird hairdo. It even looks a bit like a young Elvis Presley. You can see why some people thought the face was an alien-built monument on Mars.
First published August 4, 2015.
NASA wasn't going to let the face on Mars go without an explanation. The Mars Global Surveyor cleared things up for good in 2001 by taking a fresh image of the face. The newer, sharper, higher-resolution picture shows a much blobbier, less stark formation. In short, it's just a mesa and not an alien-carved religious site.
NASA's Perseverance rover arrived on the red planet in February 2021 and has since snapped a bounty of images of the landscape in the Jezero Crater. This fantastically funny-looking rock caught the eye of space fans who laughed about its resemblance to a rear end. It earned the nickname "butt crack rock."
Apply a little imagination to this European Space Agency Mars Express view of the red planet's south pole and you'll see an angel and a heart together. ESA described it as an "angelic figure" in a December 2020 image release.
It's simply a bit of geology on display from the icy polar region where an impact crater forms the "head" and halo, and a sublimation pit (a spot where the ice turned to vapor) formed the "hand" on the left.
Yes, these shimmering, colorful clouds appeared on Mars. NASA's Curiosity rover doesn't just eye the local geology; it also documents what's happening in the sky. This view of iridescent "mother of pearl" clouds comes from March 5, 2021.
"If you see a cloud with a shimmery pastel set of colors in it, that's because the cloud particles are all nearly identical in size," said atmospheric scientist Mark Lemmon with the Space Science Institute in Colorado. "That's usually happening just after the clouds have formed and have all grown at the same rate."
This is not a Phillips-head drill bit on Mars, but it's fun to pretend. Citizen scientist Kevin Gill spotted this odd, small rock in a Curiosity rover image from late 2020 and cracked a joke about it looking like a drill bit.
Software engineer and citizen scientists Kevin Gill has a knack for finding funny Mars rocks in rover images. He spotted this brachiosaurus-shaped rock as snapped by the Perseverance rover on Mars in April 2021. Unfortunately, we've seen no evidence of real dinosaurs on Mars, and we're still looking for signs of ancient microbial life.
The HiRise camera team for NASA's Mars Reconnaissance Orbiter spacecraft spotted a Planters Mr. Peanut mascot lookalike in this collection of pits on Mars. "The south polar residual cap is constantly changing as carbon dioxide sublimates from steep slopes, enlarging pits, and condenses on flat areas, filling pits," wrote planetary geologist Alfred McEwen in a HiRise statement in May 2021.
I think this looks like Mr. Peanut spawning Baby Nut, which is even weirder than if it was just Mr. Peanut alone.
Not a boot. Not a bot. This tiny rock on Mars captured attention in early 2019 thanks to its resemblance to a boot or a robot leg. It's neither of those things, but it is a fun shape. The images comes from NASA's Curiosity rover.
NASA's Mars Reconnaissance Orbiter caught sight of some wild dust devils tracks on Mars in late 2018. They look like claw marks, and they pop out thanks to the image processing done on this view from the spacecraft's HiRise camera. Mars is a very windy place and dust devils are common.
If this looks like it was made by humans, it's because it was. NASA's Perseverance rover landed on Mars in February 2021 and it left some debris behind on the ground when it dropped an ejectable belly pan on purpose. The pan acted as a protective cover for the rover's sampling system, which will allow it to collect and cache rock samples for a later mission to come pick up. After landing, the cover was no longer needed.
NASA's Perseverance rover snapped a view of this odd rock on March 2021. If you look closely just to the right of center, you can see a series of tiny marks where the rover's laser zapped it. This was the first celebrity rock of the rover's expedition as scientists and space fans questioned if was a weathered piece of bedrock, a chunk or Mars thrown from somewhere else by an impact event, or possibly a meteorite.
NASA's Mars Reconnaissance Orbiter viewed the "Happy Face Crater" on Mars in both 2011 and 2020 and found some changes in its complexion. You can see how it got its nickname. The crater is located in the south pole region and the difference in darkness of the features is due to the changing frost cover on the ground.
NASA's Curiosity rover snapped this view of a dark, shiny boulder on Mars on Dec. 6, 2020. The overall view is lovely, but the boulder was a bit of a mystery for how it stood out against the surrounding landscape. It's possible the boulder could be a meteorite or was perhaps deposited there from elsewhere on Mars.
Mars has a volcanic past, but there have been questions about whether it's been volcanically active more recently in its history. A research team suggested a "mysterious dark deposit" seen here could be evidence of an explosive volcanic deposit from within the last 50,000 years. For size, the deposit covers an area slightly larger than Washington DC.
This is exactly what my misshapen pancakes look like on Sunday mornings. NASA's Curiosity rover snapped this shiny, flattish rock in November 2020, leading space fans to compare it with various food items, including pancakes and melted chocolate ice cream. The rock may have been polished to a sheen thanks to wind and sand action.
Mark one up for the funny-bone file. NASA's Curiosity rover sent a photo back to Earth in 2014 that showed a very odd rock shaped a bit like a femur bone from a human thigh. Scientists obligingly explained that the unusual shape was most likely the product of erosion by wind or water. If NASA ever did amazingly find human remains on Mars, scientists would want to shout it from the rooftops.
This view from NASA's Mars Reconnaissance Orbiter, snapped in February 2016, shows some strange formations on the surface of the red planet. The dark, raised areas are a series of dunes that look a lot like the dots and dashes of Morse code.
Unfortunately, the code spells out gibberish. Planetary scientist Veronica Bray analyzed the dune image and told Gizmodo the code works out to read "NEE NED ZB 6TNN DEIBEDH SIEFI EBEEE SSIEI ESEE SEEE !!"
There's a fish-shaped rock on Mars, but there's no actual fish there. NASA's Curiosity rover caught this unusual formation on camera and UFO and alien fans got excited about it. The rock's shape and the lighting at the time of the photo combine to create the fishy look. NASA has something to say about the possibility of fossilized bones and animals on Mars: "Mars likely never had enough oxygen in its atmosphere and elsewhere to support more complex organisms. Thus, large fossils are not likely."
It wasn't there and then it was. A jelly-doughnut-shaped object appeared rather suddenly in a set of before-and-after images from NASA's Opportunity rover on Mars. Some people believed it to be an alien fungus, but NASA was having none of that nonsense.
NASA finally solved the jelly-doughnut mystery by announcing that the rock's sudden appearance was the result of the rover dislodging it by driving over it. Sadly, NASA has still not discovered snacks on Mars.
There's nothing edible here. These hematite-rich spherules are known by the cute nickname "blueberries." NASA's Mars Opportunity rover spotted the small, BB-sized pebbles in 2004 near the Fram Crater.
Opportunity got a good look at hematite-rich "blueberries" in 2004, but it also picked up a view of this unusual formation in 2012 at an outcrop named Kirkwood.
"The spherules at Kirkwood do not have the iron-rich composition of the blueberries. They also differ in concentration, distribution and structure," NASA says. The space agency calls them "puzzling." You can see the work of erosion on some of the tiny spheres.
Admittedly, this formation spotted by NASA's Mars Reconnaissance Orbiter looks a lot like a tadpole or even a yo-yo or sperm. In actuality, it's a circular crater, but the tail has been carved out by water movement.
"We can infer that water is flowing outward because we have the necessary terrain-height information," the space agency said in February 2018. While the planet had a long-distant watery past, it doesn't currently host any amphibian life as far as we know.
A peculiar jet appears far back in this scenic Mars landscape photo taken by NASA's Opportunity rover in 2016. It's actually a dust devil, much like we experience here on Earth. Towering dust devils are weather hazards on Mars and they're something future human visitors will need to be prepared to handle.
In December 2017, A popular blog for UFO enthusiasts posted a close-up look at this spherical object spotted by NASA's Curiosity rover and suggested it was a cannonball left over from a war on the red planet. NASA's rover team responded with a Twitter message pointing out how the concretion is less than a quarter inch (5 mm) in size and is actually made up of calcium sulfate, sodium and magnesium.
A cloud of particles puffs upward at a steep cliff in this 2010 image from NASA's Mars Reconnaissance Orbiter. This isn't the sign of a factory on Mars, but instead is "likely the result of an avalanche or fall of mostly carbon-dioxide frost." According to NASA, this sort of event happens mainly during the planet's springtime, which roughly corresponds to April and early May on Earth.
The Mars jelly doughnut didn't work out, but NASA wasn't done with food-shaped formations on the red planet just yet. An image from the Mars Reconnaissance Orbiter from late 2014 showed a strange waffle-shaped island on the planet's surface. The 1.2-mile-wide feature is located in an area of lava flows. It's not evidence of waffle irons on Mars, but it might be the result of lava pushing the formation up from below.
Even NASA gets excited for Game of Thrones, which is a good explanation for why the space agency described this Mars Reconnaissance Orbiter image as "Dragon Scales of Mars."
The scaly pattern doesn't come from a mythical creature, but rather through ancient landscape processes involving erosion. "The nature of the water responsible for the alteration, and how it interacted with the rock to form the clay, remains poorly understood," NASA said when it released the evocative image in July 2017.
Everybody likes shiny things. We like them even more when they pop up seemingly out of context on faraway planets. That happened in 2012 when NASA's Curiosity rover spotted a bright, shiny object tucked into the dull Martian soil. For perspective, the entire image covers an area just 1.6 inches across. NASA scientists confirmed the tiny bright bit is simply part of the geology of Mars.
Take a look at the center of this image from NASA's Curiosity rover. You might see a long-handled spoon stretching out over the landscape, casting a shadow below. Is this a sign that cooking is a popular hobby on Mars? Unfortunately, no. Mars doesn't have the same pull of gravity we have on Earth, so fragile formations like this one have a chance of holding up and not just crumbling down to the ground.
In 2017, NASA's Mars Reconnaissance Orbiter looked down and snapped this image of a bizarre-looking formation in a region known as Noctis Labyrinthus, which translates to "labyrinth of the night." The wavy areas around this mesa are sand dunes.
"Heavily eroded, with clusters of boulders and sand dunes on its surface, this layered mesa is probably comprised of sedimentary deposits that are being exhumed as it erodes," NASA says.
NASA's Curiosity rover sent back a curious photo in 2014 showing a blip of light on the horizon of Mars. The image excited UFO fans, who speculated about the light's source, wondering if it might be evidence of alien activity.
NASA scientist Doug Ellison rained on the extraterrestrial parade with the explanation that the blip was likely caused by a cosmic ray hit, the result of high-energy particles flying through space.
The Mars Curiosity rover has been at the center of quite a few unusual-object sightings on the red planet. A famous incident occurred in 2012 when the rover noticed a shiny object on the ground that didn't match its surroundings. Speculation ranged from jokes about Jimmy Hoffa's cufflink to it being an AOL CD. The explanation turned out to be pretty benign when NASA announced the object was a small plastic piece of the rover itself that had fallen off.
That weird shiny object spotted by NASA's Curiosity rover had an anticlimactic explanation. It was just a shred of plastic from the rover itself. This close-up image comes from the rover's ChemCam and helped NASA scientists determine the origin of the Martian interloper. NASA described it as "likely benign," which should leave the door open just enough for us to image the presence of a human-hungry alien race hiding out on the red planet.
NASA's Spirit rover delivered an image in 2007 showing a view of craggy little rock formations across the surface of Mars. One dramatically shaded formation stood out in the form of what looked like a little walking humanoid (either that or Bigfoot).
Popular UFO blog UFO Sightings Daily ran with speculation that the rock formation is a female figure likely made by aliens. The Planetary Society was quick to call the object an optical illusion and another excellent example of pareidolia, the tendency for our minds to assign familiar patterns to random shapes or sounds.
It can be hard to judge the size of objects in close-up photos from Mars. This image from NASA's Curiosity rover shows some stick-like figures, but they're only about a quarter-inch (6 millimeters) long. Scientists speculate they may be crystals or minerals that filled in spaces where crystals had formed, but then dissolved.
The Curiosity rover Twitter account shared a look at these formations in January 2018 and got a lot of snarky speculation in return. Twitter users suggested the stick figures looked like everything from tire tracks to Viking runes.
In October 2016, NASA's Curiosity rover spotted a weird little iron meteorite during its explorations around the base of Mount Sharp in the Gale crater on Mars. The rock would look small sitting in the palm of your hand, but the rover's close-up view shows the intricacies of the meteorite's surface. Researchers named the meteorite Egg Rock.
NASA posted this Mars Reconnaissance Orbiter image in March 2018 with the dramatic title "The Case of the Martian Boulder Piles." Look past the dark slug-like sand dunes and instead contemplate the open spaces. It contains a surprisingly orderly series of boulder piles.
NASA scientists suggest the neat piles could have been caused by a "frost heave" process with freeze-and-thaw cycles pushing the rocks into tidy shapes. A similar process has been observed here on Earth.
President Donald Trump makes a cameo appearance on Mars in this 2009 image from NASA's Opportunity rover that hit the news in 2016. It's an excellent example of pareidolia, the same psychological phenomenon that lets us see dragons or rabbits in clouds. The rock does bear a resemblance to him, complete with over-swept hair.
NASA isn't offering any definitive answers on this odd round pit seen by the Mars Reconnaissance Orbiter in 2017, but the circular formation is likely a collapse pit or an impact crater.
The pit is located in the region of the planet's south pole. The late-summer, low-sun timing of the image really makes the circle stand out from the surrounding landscape.
There's more than one woman-shaped rock on Mars. This image from the Mars Curiosity rover excited alien theorists earlier in 2015. The small, shadowy object inside the red circle does look a little bit like a statuette of a lady in a dress. All it takes is a strong imagination.
"It's really easy to pick out rocks or other things that look like something else in pictures like this," NASA media-relations specialist Guy Webster told CNET.
NASA's Mars Curiosity rover snapped a photo that could have blended in with a hundred other Mars photos in July 2015. However, this particular photo earned itself a measure of infamy when a Facebook group enhanced a close-up of one tiny piece of the picture and unveiled what looked like a weird crab monster hiding out in the shadows. It could also pass as Cthulhu.
Ultimately, the crab creature of Mars is just a fun interplay between light and shadow. It's still just a rock formation at heart.
It's fun to imagine what aliens on Mars might look like if they were real. You might conjure up images of big heads and large, black eyes, or perhaps something with crazy tentacles and sharp teeth. UFO enthusiasts imagined a bigger, hairier version of alien life when they spotted what looked like a Sasquatch skull among the landscape debris on the red planet.
The image comes from NASA's Curiosity rover from early 2016. Squint and you can imagine the random rock looking a bit like a skull with a round dome and a large eye socket. Is it really a Bigfoot skull? No. It's still just a rock, but hopefully it'll inspire some fun sci-fi stories about the great Sasquatch of Mars.
On the left is a cropped view of an image from the Mars Opportunity rover. On the right is a Neo-Assyrian attendant god statue from the British Museum. Notice a little resemblance? So did some UFO fans, who brought attention to the face-like rock found on the red planet.
As with all Mars rocks that look like Earth objects, it's really a combination of human imagination and fortuitous light rather than a sign of an alien civilization with a penchant for carving sculptures.
The European Space Agency's ExoMars mission suffered a setback when its Schiaparelli lander crash-landed Mars in October 2016. NASA's Mars Reconnaissance Orbiter took this photo of the crash site to help ESA investigators work out what happened to the ill-fated lander. The large dark spot shows the impact site. Other highlighted areas show the front heatshield, parachute and rear heatshield.
These distinctive-looking round shapes are found in the Eagle Crater on Mars. Take a close look at the one on the upper right-hand side. Notice a small dot inside? That's the lander that carried the Mars Opportunity rover down to the planet's surface in 2004. A small dot toward the lower left-hand corner of the image is the lander's backshell and parachute.
NASA shared this fresh view of the landing gear in the crater in April 2017.
This strange landscape photo might remind you of worm tracks or some strange ant farm. What you're actually seeing here is a 2016 Mars Reconnaissance Orbiter view of Mars' south pole.
"The polar cap is made from carbon dioxide (dry ice), which does not occur naturally on the Earth. The circular pits are holes in this dry ice layer that expand by a few meters each Martian year," NASA explains.
Pucker up! This Mars rock looks like it wants to lay a kiss on you. The unusual formation has the appearance of a human-like face with an eye, nose, forehead, chin and smooch-ready lips.
Alien fans spotted the rock while looking through images sent back by NASA's Mars Curiosity rover in late 2016. It's a fun formation, but it's not a sign of alien life on the red planet.
With a little time and effort, anyone can find rock formations that look like human or alien faces on Mars. Here are two "faces" with their features pointed out. This image comes from NASA's Curiosity rover, which snapped the landscape view in late 2016.
All it takes is some imagination to harness the human power of pareidolia, a phenomenon that causes people to see recognizable faces and shapes in unrelated objects.
What does this look like to you? Claw marks? Eyelashes? This is a look at a series of squiggly lines captured by NASA's Mars Reconnaissance Orbiter in 2017. The space agency says the linear gullies are likely caused by dry ice sliding down sandy dune slopes.
Some Mars-watching space fans on Flickr enhanced an image captured by the Mars Curiosity in early 2013 to highlight what appears to be a hunk of metal just hanging out on the red planet's surface. The likely explanation is a lot less fun than imagining a race of metal-forging aliens. The object is probably a piece of a meteorite or the result of strange lighting. It's definitely not an alien fertility effigy.
NASA's Curiosity rover got up close to investigate this interesting shiny object in November 2018. The Curiosity team suspected it might be a meteorite, but didn't want to say for sure without confirming the identification by examining the rock's composition.
This odd-looking object caught the attention of NASA's Curiosity rover team in August 2018. The space agency was concerned it might be a small piece of the rover, but a closer look showed the potential "foreign object debris" to be a flake-like bit of the natural Mars landscape.
Wakka, wakka, wakka. NASA's Mars Reconaissance Orbiter caught sight of this Pac-Man imagery on Mars in early 2018. The shape of the retro video game star appears thanks to an impact crater with a crescent-shaped barchan sand dune inside.
These lovely spiral patterns aren't petroglyphs. The swirls are known as lava coils. "When two lava flows in opposite directions mingle and swirl, the coils are the hardened results," says the University of Arizona team that works with the HiRise camera on the Mars Reconnaissance Orbiter.
Mee-mee-mee-mee. A familiar Muppet face appeared on Mars in this mid-2018 image from NASA's Mars Reconnaissance Orbiter. The formation in the south pole region resembles Beaker the lab assistant from The Muppet Show. The southern polar cap is covered with frozen carbon dioxide and is full of pits and mesas that can take on unusual shapes.
The European Space Agency's Mars Express orbiter snapped this Mars view on Sept. 24, 2018. Some people who saw the image thought it might show an active volcano smoking on the planet's surface. What we're actually seeing is a cloud that happens to have formed near the Arsia Mons volcano. There's no eruption here.