Why does NASA's Perseverance rover keep taking pictures of this maze on Mars?
If you've spent any time perusing the carousel of raw images from NASA's Perseverance Mars rover, you might have stumbled across an odd subject: a tiny, intricate maze etched into a small plate, photographed over and over again.
Why is the Perseverance rover so obsessed with this little labyrinth? It turns out the maze is a calibration target — one of 10 for Perseverance's Scanning Habitable Environments with Raman & Luminescence for Organics and Chemicals instrument, otherwise known for its fun acronym, SHERLOC.
This Sherlock Holmes–inspired tool is designed to detect organic compounds and other minerals on Mars that could indicate signs of ancient microbial life. To do that accurately, the system must be carefully calibrated, and that's where the maze comes in.
Located on the rover's seven-foot (2.1-meter) robotic arm, SHERLOC uses spectroscopic techniques — specifically Raman and fluorescence spectroscopy — to analyze Martian rocks. In order to ensure accurate measurements, it must routinely calibrate its tools using a set of reference materials with specific properties. These are mounted on a plate attached to the front of the rover's body: the SHERLOC Calibration Target.
"The calibration targets serve multiple purposes, which primarily include refining the SHERLOC wavelength calibration, calibrating the SHERLOC laser scanner mirror, and monitoring the focus and state of health of the laser," Kyle Uckert, deputy principal investigator for SHERLOC at NASA's Jet Propulsion Laboratory, tells Space.com
The target is arranged in two rows, each populated with small patches of carefully selected materials.
The top row includes three critical calibration materials: aluminum gallium nitride (AlGaN) on sapphire discs; the UV-scattering material Diffusil; and Martian meteorite SaU008, whose mineral makeup is already known and helps align wavelength calibration with real Martian geology.
This is also where you'll find the maze. Why a maze? "SHERLOC is all about solving puzzles, and what better puzzle than a maze!" says Uckert. The purpose of the maze target is to calibrate the positioning of the laser scanner mirror and characterize the laser's focus, which requires a target with sharply contrasting spectral responses. The maze serves this purpose well."
The maze is made of chrome-plated lines just 200 microns thick (about twice the width of a human hair) printed onto silica glass. "There are no repeating patterns and the spectrum of the chrome plating is distinct from the underlying silica glass," says Uckert. That makes it possible to measure the laser's focus and accuracy with extreme precision.
If you look closely at the maze, you'll also notice a Sherlock Holmes portrait right at the center. While it's a cheeky nod to the instrument's name, it serves a practical function. "SHERLOC spectral maps can resolve the 200 micron thick chrome plated lines and the 50 micron thick silhouette of Sherlock Holmes at the center of the maze," Uckert notes.
Like the portrait, the bottom half of the SHERLOC Calibration Target also serves a dual purpose: spectral instrument calibration and spacesuit material testing. It contains five samples of materials used in modern spacesuits, including some materials you might be familiar with, like Teflon, Gore-Tex, and Kevlar. And don't miss the "fun" target in this row — there's a geocache marker backing a polycarbonate target, and it does indeed have a tie-in to Sherlock Holmes.
RELATED STORIES:
— Perseverance rover's Mars samples show traces of ancient water, but NASA needs them on Earth to seek signs of life
— Perseverance Mars rover finds 'one-of-a-kind treasure' on Red Planet's Silver Mountain
— Perseverance Mars rover becomes 1st spacecraft to spot auroras from the surface of another world
These materials are actively being tested under Mars conditions to determine how they hold up over time in situ, which is crucial for planning human exploration of the Red Planet. "Note that we use all of these materials to fine-tune SHERLOC," adds Uckert. "As a bonus, the spacesuit materials support unique science that will help keep future astronauts safe."
Now, if all these Sherlock Holmes–related Easter eggs on the SHERLOC Calibration Target aren't enough for you, there's one final link. SHERLOC has a color camera as part of its instrumentation suite that sometimes images the target, and it's called the Wide Angle Topographic Sensor for Operations and eNgineering.
Yes, SHERLOC's sidekick is called WATSON.
Hashtags

Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles

an hour ago
The biggest piece of Mars on Earth is going up for auction in New York
NEW YORK -- For sale: A 54-pound (25-kilogram) rock. Estimated auction price: $2 million to $4 million. Why so expensive? It's the largest piece of Mars ever found on Earth. Sotheby's in New York will be auctioning what's known as NWA 16788 on Wednesday as part of a natural history-themed sale that also includes a juvenile Ceratosaurus dinosaur skeleton that's more than 6 feet (2 meters) tall and nearly 11 feet (3 meters) long. According to the auction house, the meteorite is believed to have been blown off the surface of Mars by a massive asteroid strike before traveling 140 million miles (225 million kilometers) to Earth, where it crashed into the Sahara. A meteorite hunter found it in Niger in November 2023, Sotheby's says. The red, brown and gray hunk is about 70% larger than the next largest piece of Mars found on Earth and represents nearly 7% of all the Martian material currently on this planet, Sotheby's says. It measures nearly 15 inches by 11 inches by 6 inches (375 millimeters by 279 millimeters by 152 millimeters). 'This Martian meteorite is the largest piece of Mars we have ever found by a long shot," Cassandra Hatton, vice chairman for science and natural history at Sotheby's, said in an interview. 'So it's more than double the size of what we previously thought was the largest piece of Mars.' It is also a rare find. There are only 400 Martian meteorites out of the more than 77,000 officially recognized meteorites found on Earth, Sotheby's says. Hatton said a small piece of the red planet remnant was removed and sent to a specialized lab that confirmed it is from Mars. It was compared with the distinct chemical composition of Martian meteorites discovered during the Viking space probe that landed on Mars in 1976, she said. The examination found that it is an 'olivine-microgabbroic shergottite,' a type of Martian rock formed from the slow cooling of Martian magma. It has a course-grained texture and contains the minerals pyroxene and olivine, Sotheby's says. It also has a glassy surface, likely due to the high heat that burned it when it fell through Earth's atmosphere, Hatton said. 'So that was their first clue that this wasn't just some big rock on the ground,' she said. The meteorite previously was on exhibit at the Italian Space Agency in Rome. Sotheby's did not disclose the owner. It's not clear exactly when the meteorite hit Earth, but testing shows it probably happened in recent years, Sotheby's said. The juvenile Ceratosaurus nasicornis skeleton was found in 1996 near Laramie, Wyoming, at Bone Cabin Quarry, a gold mine for dinosaur bones. Specialists assembled nearly 140 fossil bones with some sculpted materials to recreate the skeleton and mounted it so it's ready to exhibit, Sotheby's says. The skeleton is believed to be from the late Jurassic period, about 150 million years ago, Sotheby's says. It's auction estimate is $4 million to $6 million. Ceratosaurus dinosaurs were bipeds with short arms that appear similar to the Tyrannosaurus rex, but smaller. Ceratosaurus dinosaurs could grow up to 25 feet (7.6 meters) long, while the Tyrannosaurs rex could be 40 feet (12 meters) long. The skeleton was acquired last year by Fossilogic, a Utah-based fossil preparation and mounting company. Wednesday's auction is part of Sotheby's Geek Week 2025 and features 122 items, including other meteorites, fossils and gem-quality minerals.


Tom's Guide
an hour ago
- Tom's Guide
3 best sci-fi movies on Prime Video right now
Looking for something intellectual to chew on? Prime Video's sci-fi movies section is bigger than ever, but with so many titles flooding in regularly, you might have trouble figuring out what to watch first. While flashy blockbusters and well-known franchises tend to hog the spotlight, there's a deep bench of underrated, thought-provoking science fiction films that deserve your time. Some of those may very well be blockbusters on their own, like "Interstellar" — but when's the last time you took a moment to appreciate them? Whether you're into alternate realities, time loop mind-benders or eerie glimpses of the future, there are tons of gems on the platform to dig into. Here are three of the best sci-fi movies on Prime Video that you can stream right now. "Stargate" (the movie, not the series) kicks off with one of the most intriguing premises in sci-fi: What if an ancient alien device unearthed in Egypt turned out to be a gateway to another planet? When one milquetoast linguist (James Spader) deciphers the symbols on the mysterious artifact, he's swept up into a top-secret military expedition led by a gritty, no-nonsense colonel (Kurt Russell). On the other side of the stargate lies a distant world that resembles ancient Egypt, ruled by a powerful alien posing as a god. And it's this ragtag team's mission to understand it, come hell or high water. Watch "Stargate" on Prime Video now "Coherence" begins as a casual dinner party between old friends but spirals into chaos when a comet passes overhead and warps reality itself. The power flickers and phone signals vanish, and the group of friends slowly begins to realize that their neighborhood may now contain multiple versions of themselves, each making different choices in diverging timelines. Get instant access to breaking news, the hottest reviews, great deals and helpful tips. What follows is a race to determine who's who, who's a potential other, and what their other selves' true motives are. What's more, how do they get back to normal and to their "normal" world? This mind-bending cult favorite will keep you guessing until the very end. Watch "Coherence" on Prime Video now In a future where Earth is slowly becoming uninhabitable, former NASA pilot Joseph Cooper (Matthew McConaughey) is recruited for a last-ditch mission. His job is to travel through a wormhole in search of a new home for mankind. No pressure, right? What begins as a seemingly benign spacefaring journey quickly becomes something deeper as Cooper realizes nearly two decades have passed during his journey. He must come to terms with his startling findings and the future awaiting humanity as time ticks down. Watch "Interstellar" on Prime Video now


Boston Globe
3 hours ago
- Boston Globe
The biggest piece of Mars on Earth is going up for auction in New York
The red, brown and gray hunk is about 70% larger than the next largest piece of Mars found on Earth and represents nearly 7% of all the Martian material currently on this planet, Sotheby's says. It measures nearly 15 inches by 11 inches by 6 inches (375 millimeters by 279 millimeters by 152 millimeters). Get Starting Point A guide through the most important stories of the morning, delivered Monday through Friday. Enter Email Sign Up 'This Martian meteorite is the largest piece of Mars we have ever found by a long shot,' Cassandra Hatton, vice chairman for science and natural history at Sotheby's, said in an interview. 'So it's more than double the size of what we previously thought was the largest piece of Mars.' Advertisement It is also a rare find. There are only 400 Martian meteorites out of the more than 77,000 officially recognized meteorites found on Earth, Sotheby's says. Hatton said a small piece of the red planet remnant was removed and sent to a specialized lab that confirmed it is from Mars. It was compared with the distinct chemical composition of Martian meteorites discovered during the Viking space probe that landed on Mars in 1976, she said. Advertisement The examination found that it is an 'olivine-microgabbroic shergottite,' a type of Martian rock formed from the slow cooling of Martian magma. It has a course-grained texture and contains the minerals pyroxene and olivine, Sotheby's says. It also has a glassy surface, likely due to the high heat that burned it when it fell through Earth's atmosphere, Hatton said. 'So that was their first clue that this wasn't just some big rock on the ground,' she said. The meteorite previously was on exhibit at the Italian Space Agency in Rome. Sotheby's did not disclose the owner. It's not clear exactly when the meteorite hit Earth, but testing shows it probably happened in recent years, Sotheby's said. The juvenile Ceratosaurus nasicornis skeleton was found in 1996 near Laramie, Wyoming, at Bone Cabin Quarry, a gold mine for dinosaur bones. Specialists assembled nearly 140 fossil bones with some sculpted materials to recreate the skeleton and mounted it so it's ready to exhibit, Sotheby's says. The skeleton is believed to be from the late Jurassic period, about 150 million years ago, Sotheby's says. It's auction estimate is $4 million to $6 million. Ceratosaurus dinosaurs were bipeds with short arms that appear similar to the Tyrannosaurus rex, but smaller. Ceratosaurus dinosaurs could grow up to 25 feet (7.6 meters) long, while the Tyrannosaurs rex could be 40 feet (12 meters) long. The skeleton was acquired last year by Fossilogic, a Utah-based fossil preparation and mounting company. Advertisement Wednesday's auction is part of Sotheby's Geek Week 2025 and features 122 items, including other meteorites, fossils and gem-quality minerals.