Signs of Life on Mars? NASA’s Perseverance Rover Begins the Hunt
After testing a bristling array of instruments on its robotic arm, NASA’s latest Mars rover gets down to business: probing rocks and dust for evidence of past life.
NASA’s Mars 2020 Perseverance rover has begun its search for signs of ancient life on the Red Planet. Flexing its 7-foot (2-meter) mechanical arm, the rover is testing the sensitive detectors it carries, capturing their first science readings. Along with analyzing rocks using X-rays and ultraviolet light, the six-wheeled scientist will zoom in for closeups of tiny segments of rock surfaces that might show evidence of past microbial activity.
Called PIXL, or Planetary Instrument for X-ray Lithochemistry, the rover’s X-ray instrument delivered unexpectedly strong science results while it was still being tested, said Abigail Allwood, PIXL’s principal investigator at NASA’s Jet Propulsion Laboratory in Southern California. Located at the end of the arm, the lunchbox-size instrument fired its X-rays at a small calibration target – used to test instrument settings – aboard Perseverance and was able to determine the composition of Martian dust clinging to the target.
“We got our best-ever composition analysis of Martian dust before it even looked at rock,” Allwood said.
That’s just a small taste of what PIXL, combined with the arm’s other instruments, is expected to reveal as it zeroes in on promising geological features over the weeks and months ahead.
Scientists say Jezero Crater was a crater lake billions of years ago, making it a choice landing site for Perseverance. The crater has long since dried out, and the rover is now picking its way across its red, broken floor.
“If life was there in Jezero Crater, the evidence of that life could be there,” said Allwood, a key member of the Perseverance “arm science” team.
To get a detailed profile of rock textures, contours, and composition, PIXL’s maps of the chemicals throughout a rock can be combined with mineral maps produced by the SHERLOCinstrument and its partner, WATSON. SHERLOC – short for Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals – uses an ultraviolet laser to identify some of the minerals in the rock, while WATSON takes closeup images that scientists can use to determine grain size, roundness, and texture, all of which can help determine how the rock was formed.
Early WATSON closeups have already yielded a trove of data from Martian rocks, the scientists said, such as a variety of colors, sizes of grains in the sediment, and even the presence of “cement” between the grains. Such details can provide important clues about formation history, water flow, and ancient, potentially habitable Martian environments. And combined with those from PIXL, they can provide a broader environmental and even historical snapshot of Jezero Crater.
“What is the crater floor made out of? What were the conditions like on the crater floor?” asks Luther Beegle of JPL, SHERLOC’s principal investigator. “That does tell us a lot about the early days of Mars, and potentially how Mars formed. If we have an idea of what the history of Mars is like, we’ll be able to understand the potential for finding evidence of life.”
The Science Team
While the rover has significant autonomous capabilities, such as driving itself across the Martian landscape, hundreds of earthbound scientists are still involved in analyzing results and planning further investigations.
“There are almost 500 people on the science team,” Beegle said. “The number of participants in any given action by the rover is on the order of 100. It’s great to see these scientists come to agreement in analyzing the clues, prioritizing each step, and putting together the pieces of the Jezero science puzzle.”
That will be critical when the Mars 2020 Perseverance rover collects its first samples for eventual return to Earth. They’ll be sealed in superclean metallic tubes on the Martian surface so that a future mission could collect them and send back to the home planet for further analysis.
Despite decades of investigation on the question of potential life, the Red Planet has stubbornly kept its secrets.
“Mars 2020, in my view, is the best opportunity we will have in our lifetime to address that question,” said Kenneth Williford, the deputy project scientist for Perseverance.
The geological details are critical, Allwood said, to place any indication of possible life in context, and to check scientists’ ideas about how a second example of life’s origin could come about.
Combined with other instruments on the rover, the detectors on the arm, including SHERLOC and WATSON, could make humanity’s first discovery of life beyond Earth.
More About the Mission
A key objective for Perseverance’s mission on Mars is astrobiology, including the search for signs of ancient microbial life. The rover will characterize the planet’s geology and past climate, pave the way for human exploration of the Red Planet, and be the first mission to collect and cache Martian rock and regolith (broken rock and dust).
Subsequent NASA missions, in cooperation with ESA (European Space Agency), would send spacecraft to Mars to collect these sealed samples from the surface and return them to Earth for in-depth analysis.
The Mars 2020 Perseverance mission is part of NASA’s Moon to Mars exploration approach, which includes Artemis missions to the Moon that will help prepare for human exploration of the Red Planet.
JPL, which is managed for NASA by Caltech in Pasadena, California, built and manages operations of the Perseverance rover.
NASA Perseverance Mars Rover to Acquire First Sample
NASA is making final preparations for its Perseverance Mars rover to collect its first-ever sample of Martian rock, which future planned missions will transport to Earth. The six-wheeled geologist is searching for a scientifically interesting target in a part of Jezero Crater called the “Cratered Floor Fractured Rough.”
This important mission milestone is expected to begin within the next two weeks. Perseverance landed in Jezero Crater Feb. 18, and NASA kicked off the rover mission’s science phase June 1, exploring a 1.5-square-mile (4-square-kilometer) patch of crater floor that may contain Jezero’s deepest and most ancient layers of exposed bedrock.
“When Neil Armstrong took the first sample from the Sea of Tranquility 52 years ago, he began a process that would rewrite what humanity knew about the Moon,” said Thomas Zurbuchen, associate administrator for science at NASA Headquarters. “I have every expectation that Perseverance’s first sample from Jezero Crater, and those that come after, will do the same for Mars. We are on the threshold of a new era of planetary science and discovery.”
It took Armstrong 3 minutes and 35 seconds to collect that first Moon sample. Perseverance will require about 11 days to complete its first sampling, as it must receive its instructions from hundreds of millions of miles away while relying on the most complex and capable, as well as the cleanest, mechanism ever to be sent into space – the Sampling and Caching System.
Precision Instruments Working Together
The sampling sequence begins with the rover placing everything necessary for sampling within reach of its 7-foot (2-meter) long robotic arm. It will then perform an imagery survey, so NASA’s science team can determine the exact location for taking the first sample, and a separate target site in the same area for “proximity science.”
“The idea is to get valuable data on the rock we are about to sample by finding its geologic twin and performing detailed in-situ analysis,” said science campaign co-lead Vivian Sun, from NASA's Jet Propulsion Laboratory in Southern California. “On the geologic double, first we use an abrading bit to scrape off the top layers of rock and dust to expose fresh, unweathered surfaces, blow it clean with our Gas Dust Removal Tool, and then get up close and personal with our turret-mounted proximity science instruments SHERLOC, PIXL, and WATSON.”
SHERLOC (Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals), PIXL (Planetary Instrument for X-ray Lithochemistry), and the WATSON (Wide Angle Topographic Sensor for Operations and eNgineering) camera will provide mineral and chemical analysis of the abraded target. Perseverance’s SuperCam and Mastcam-Z instruments, both located on the rover’s mast, will also participate. While SuperCam fires its laser at the abraded surface, spectroscopically measuring the resulting plume and collecting other data, Mastcam-Z will capture high-resolution imagery.
Working together, these five instruments will enable unprecedented analysis of geological materials at the worksite.
“After our pre-coring science is complete, we will limit rover tasks for a sol, or a Martian day,” said Sun. “This will allow the rover to fully charge its battery for the events of the following day.”
Sampling day kicks off with the sample-handling arm within the Adaptive Caching Assembly retrieving a sample tube, heating it, and then inserting it into a coring bit. A device called the bit carousel transports the tube and bit to a rotary-percussive drill on Perseverance’s robotic arm, which will then drill the untouched geologic “twin” of the rock studied the previous sol, filling the tube with a core sample roughly the size of a piece of chalk.
Perseverance’s arm will then move the bit-and-tube combination back into bit carousel, which will transfer it back into the Adaptive Caching Assembly, where the sample will be measured for volume, photographed, hermetically sealed, and stored. The next time the sample tube contents are seen, they will be in a clean room facility on Earth, for analysis using scientific instruments much too large to send to Mars.
“Not every sample Perseverance is collecting will be done in the quest for ancient life, and we don’t expect this first sample to provide definitive proof one way or the other,” said Perseverance project scientist Ken Farley, of Caltech. “While the rocks located in this geologic unit are not great time capsules for organics, we believe they have been around since the formation of Jezero Crater and incredibly valuable to fill gaps in our geologic understanding of this region – things we’ll desperately need to know if we find life once existed on Mars.”
More About the Mission
A key objective for Perseverance’s mission on Mars is astrobiology, including the search for signs of ancient microbial life. The rover will characterize the planet’s geology and past climate, pave the way for human exploration of the Red Planet, and be the first mission to collect and cache Martian rock and regolith.
The Mars 2020 Perseverance mission is the first step in NASA’s Mars Sample Return Campaign. Subsequent NASA missions, now in development in cooperation with the European Space Agency, would send spacecraft to Mars to collect these sealed samples from the surface and return them to Earth for in-depth analysis.
The Mars 2020 Perseverance mission is part of NASA’s Moon to Mars exploration approach, which includes Artemis missions to the Moon that will help prepare for human exploration of the Red Planet.
Ingenuity completes 10th flight on Mars, Perseverance starts search for life
On July 24, 2021, NASA’s Ingenuity Mars helicopter successfully completed its 10th and most daring flight on the red planet — a major milestone for the Ingenuity mission. The helicopter, originally expected to only perform five flights on Mars, continues to assist the Perseverance rover as hoped.
Meanwhile, Perseverance itself recently began full science operations at Jezero Crater. Rover teams are finalizing testing onboard the science platform and beginning the search for signs of life on Mars.
Ingenuity’s operational history
Ingenuity landed on Mars on February 18, 2021 attached to the underside of the Perseverance rover and protected by a debris shield. A little over a month after landing, on March 21, the debris shield was dropped by Perseverance in preparation for deployment of Ingenuity.
Perseverance placed Ingenuity onto the surface of Mars on April 3 at a location designated “Wright Brothers Field.” Ingenuity teams then began a series of tests with the helicopter to ensure it was in good shape to begin flying.
After completing rotor tests and surviving Martian nights, Perseverance drove to Van Zyl Overlook to observe Ingenuity’s first flight. Overcoming a command sequence issue, Ingenuity performed the first powered flight of any aircraft on another planet on April 19, 2021.
Flight 1, a demonstration hop, consisted of a simple vertical takeoff, an ascent to three meters, a stable hover for 30 seconds, a 90-degree turn, and a descent back to the surface. The flight lasted a total of 39.1 seconds and was a complete success.
Ingenuity’s teams began preparing for the second flight, and just three days after the first flight, the helicopter successfully performed its second.
Flight 2 consisted of a vertical takeoff, an ascent to five meters, a hover, a sideways divert of two meters to the east, a 276 degree counterclockwise turn, a divert maneuver two meters to the west, and a descent. The flight lasted 51.9 seconds, and Ingenuity traveled at a speed of 0.5 m/s.
In a continued effort to try and stay within the helicopter’s 30 day test window, Ingenuity teams began preparing for the third flight — the third in less than a week.
Flight 3 was performed on April 25 and consisted of a vertical ascent to five meters, a hover, a northward divert of 50 meters, a hover, a southward divert of 50 meters, a hover, and a descent. The flight lasted 80.3 seconds with Ingenuity traveling at 2 m/s over a total distance of 100 meters.
During the flight, Ingenuity was able to capture an image of Perseverance observing it in the distance. With this flight, JPL announced that Ingenuity had met or surpassed all of the test goals set for the helicopter’s tech demonstration and that it would begin performing more daring flights to push the limits of its design.
Ingenuity’s fourth flight was scheduled for April 29; however, no flight occurred. Upon investigation, Ingenuity teams found that the helicopter did not successfully transition into flight mode. As a result, Flight 4 was rescheduled for April 30.
Flight 4 eventually consisted of a takeoff, an ascent to five meters, a hover, a southward divert of 133 meters, a hover, a northward divert of 133 meters, a hover, and a descent. Ingenuity traveled 266 meters roundtrip at a top speed of 3.5 m/s over 117 seconds.
Up through flight four, the helicopter performed all of its takeoffs and landings at the same location: Wright Brothers Field. However, Flight 5 would see Ingenuity land in a separate location.
On May 7, Ingenuity successfully performed this flight with a 110 second travel time and a maximum velocity of 2 m/s across 129 meters distance while maintaining 10 meters altitude above the local terrain.
This flight also marked the end of Ingenuity’s technology demonstration phase, as the helicopter had not just met but surpassed all of its pre-mission planned objectives.
Flight 6 on May 23 began an operations demonstration phase, with a flight sequence consisting of a takeoff, an ascent to 10 meters, a southwest divert of 150 meters, a southerly translation of 15 meters for color imagery collection, a northeastern divert of 50 meters, a descent, and a landing in a new area known as “Airfield C”.
Flight 6 marked the first time Ingenuity landed in an area it had not previously surveyed from the air.
When Ingenuity lands in previously not surveyed regions, teams rely on HiRISE camera image data from the Mars Reconnaissance Orbiter to ensure the location meets the helicopter’s landing and take off specifications.
However, during Flight 6, Ingenuity encountered an in-flight anomaly. The first southwesterly divert was performed as planned, but approximately 54 seconds into flight, the vehicle began rapidly changing velocity and became somewhat unstable as well.
Ingenuity was able to self-correct, stay airborne, and later land just five meters from its intended touchdown area. The anomaly was traced to the helicopter’s camera navigation system marking images with the incorrect timestamps.
Following the in-flight anomaly, Flight 7 occurred on June 8, after a failed attempt on June 6 due to the same reason Flight 4 failed.
Flight 7 consisted of a takeoff, an ascent to 10 meters, a 106 meter divert to the south, a descent, and a landing in a new location, Airfield D. This flight did not use the helicopter’s camera navigation system to avoid the glitch that caused the Flight 6 anomaly.
Two weeks after Flight 7, Ingenuity successfully performed its eighth flight on June 22. The flight, which lasted 78 seconds, consisted of a takeoff from Airfield D, an ascent to 10 meters, a divert of 160 meters to the southeast, a descent, and a landing.
Like Flight 7, Ingenuity’s camera navigation system was not used during flight 8 to avoid the Flight 6 anomaly.
In pursuit of pushing the envelope even more, Flight 9 was set to be Ingenuity’s most daring flight to that time.
The helicopter, which had only traveled 266 meters in a single flight, was set to travel 625 meters southwest across the Séítah area. The flight consisted of a takeoff from Airfield E, ascent to 10 meters, a southwesterly divert of 625 meters in which a maximum velocity of 5 m/s was recorded, a descent, and a landing.
Ingenuity successfully completed the prolonged flight on July 5, and although it landed slightly short of its intended touchdown location, it managed, with this flight, to exceed the total distance the Perseverance rover itself had travel across the Martian terrain since landing.
At the completion of Flight 9, Ingenuity had an odometer reading of just over 1,600 meters, just slightly edging out Perseverance.
Flight 10 sought to introduce more complication into the flight plan, with Ingenuity set to travel to 10 different waypoints to allow its camera to gather images of an outcrop the rover team is looking to investigate.
Flight 10 occurred on July 24 and consisted of a takeoff, an ascent to 12 meters (a new Mars altitude record), a 50 meter divert to the southwest, a sideways translation to the west, a northwesterly divert, a divert to the northeast, a descent, and a landing in a new airfield.
According to Ingenuity’s teams, the helicopter remains in good health and is expected to keep flying until a major anomaly or issue prevents the rotorcraft from doing so.
Perseverance science operations well underway
Following its commissioning on June 1, Perseverance left the Octavia E Butler landing site in Jezero Crater and began the science phase of its mission.
“We are putting the rover’s commissioning phase as well as the landing site in our rearview mirror and hitting the road,” said Jennifer Trosper, Perseverance project manager at NASA’s Jet Propulsion Laboratory.
The two locations scientists are looking to study first are the Séítah area and the Crater Floor Fractured Rough area. Séítah, meaning “amidst the sand” in Navajo, is a unique geologic area with various characteristics including dunes, bedrock, ridges, and layered rocks.
The Crater Floor Fractured Rough area is comprised of bedrock and is the crater-filled floor of Jezero Crater. Here, Perseverance is expected to drill and collect its first sample of the Martian soil.
Perseverance will mostly be able to drive on the Crater Floor Fractured Rough region, but due to the unknown conditions of the Séítah area, the rover will drive along the boundary of the region for safety considerations before eventually performing a “toe-dip” maneuver with one of the Séítah sand dunes after the region and its drivability are better understood.
Once the rover has finished investigating these two areas, it will return to its landing site, where it will then drive north to begin its second science campaign.
Throughout the early portions of its mission, Perseverance will be aided by Ingenuity, which at this point is functioning as a scout for the rover. As part of Ingenuity’s operations demonstration phase, the helicopter has so far provided useful color imagery of areas of geologic interest to scientists.
One such area is “Raised Ridges” — a rocky outcrop of a geologic fracture system. During Ingenuity’s ninth flight, it flew over the area and took high-definition imagery of the outcrop. Using these images, Perseverance’s planning teams now have a better understanding of where to go and where to look for certain features on the Rocky Ridges that may be of biological importance or significance.
Part of Perseverance’s unique ability to travel and perform science stems from its 2-meter long robotic arm. At the end of this arm is a suite of instruments — including a drill, camera, and X-ray — that Perseverance can use to study the Martian surface in extreme detail.
Following extensive checkouts on Mars, the robotic arm has been cleared for full science operations, allowing Perseverance to begin fulfilling its purpose — investigating, in-situ, the Martian environment with a specific goal of searching for signs of past and present life on the Red Planet.
To fulfill this goal, Perseverance will use its drill and robotic arm to collect and store samples of the Martian surface. Using its plethora of instruments, Perseverance will analyze the area of the surface where the sample will be collected before the rover’s Adaptive Caching Assembly retrieves a sample tube from inside the rover.
The Adaptive Caching Assembly will heat the tube and then insert it into a coring bit. The bit will then be transferred to the drill on the robotic arm. The drill will then slowly lower to the surface and extract a portion of material. Meanwhile, the sample tube will collect the soil, dust, and rock. Once complete, the sample in the tube should be roughly the size of a piece of chalk.
The tube will then be inserted back into the rover, where instruments will analyze it before storing it safely inside Perseverance.
This entire process, although lengthy, is vital to Perseverance’s mission. A follow-up Sample Fetch Rover from the European Space Agency (ESA) — set to arrive in 2029 after a three-year cruise to Mars — will collect these sample tubes, which Perseverance will periodically leave behind on the Martian surface.
The sample tubes collected by the Sample Fetch Rover will be returned to Earth via a Northrop Grumman-built Mars Ascent Vehicle (a solid motor rocket that will be launched with the Sample Fetch Rover) which will meet a ESA-provided Earth Return Orbiter and capsule in Martian orbit. The orbiter will then collect the samples and return them to Earth where they can be examined thoroughly with unique instruments Perseverance cannot carry.
The ESA Earth Return Orbiter, the third of the three Mars Sample Return flights, is slated to launch in October 2026 on an Ariane 6 rocket from French Guiana three months after the Mars Ascent Vehicle and Sample Fetch Rover are scheduled to be launched from the United States.