The quest has been a long time coming. The twin Viking landers were sent to Mars in 1975 to search for signs of life on Mars. But their 1976 experiments turned up ambiguous results.
Other Mars missions have tried to build a comprehensive picture of Mars’ past, but Perseverance and its unprecedented suite of cutting-edge scientific instruments will be the first NASA mission since the Vikings to conduct robust hunts for life on Mars.
In a paper published Wednesday in the journal Science Robotics, a team of engineers breaks down the rover’s capabilities at finding microfossils buried deep within Martian rock.
NASA has previously landed four other rovers on the Red Planet, including the Curiosity rover that began traversing Mars in 2012, and is still roams Gale Crater today.
However, Perseverance has set itself apart, building on the instruments aboard Curiosity and packing many firsts for a Martian rover.
How will Perseverance look for life on Mars?
Mars is arid and dusty today — a vast, cold desert with a thin atmosphere that means any liquid water on the surface is evaporated away.
But evidence collected by previous Martian missions suggests the Red Planet was once a warm planet with a substantial atmosphere, rivers carving throughout its terrain, and lakebeds holding pools of temperate liquid water. In other words, Mars likely was habitable during its earlier years.
Perseverance will examine Mars’ Jezero Crater — a 28-mile wide, 1,600-foot deep crater located in a basin slightly north of the Martian equator — for signs of ancient life.
Jezero Crater once housed a lake estimated to have dried out 3.5 to 3.8 billion years ago, making it the perfect environment to look for signs of ancient microorganisms that may have lived in the lake’s waters.
Perseverance will not only examine Martian rocks, but the rover will also pick up the samples of rock and stow them away for a future return mission to Earth where they will be examined in a lab.
The robot is armed with nine drill bits to collect samples of Martian rock and dust, which will then move through the belly of the robot, and into the Adaptive Caching Assembly (ACA) system where they are assessed and processed.
The ACA is part of the Sampling and Caching System on the Mars rover. It’s made up of multiple stations that process, seal, and store sample tubes containing the collected Martian samples.
The assembly system contains seven motors and more than 3,000 parts, including the Sample Handling Arm that the rover will use to hold sample tubes.
Perseverance’s robotic arm will move the sample tubes between ACA stations as part of an end-to-end sampling sequence.
Persverance’s SuperCam is equipped with a laser that zaps at Martian rocks at a distance of about 20 feet. As the laser fires at the rocks, a small amount of the rock vaporizes into a hot gas called plasma, and the heat and vibration create a shockwave that makes a popping sound.
The camera and spectrometer identify the chemical makeup of the vaporized rock while the microphone listens for the popping sound. That “pop” tells scientists about the mass of the rocks, and how hard or soft it is.
Perseverance tested out its laser earlier this month, producing a mind-blowing audio clip of that precious “pew pew.” Nina Lanza, the planetary scientist and team lead for Space and Planetary Exploration at Los Alamos National Laboratory, said at the time of the first laser fire that the acoustic data itself tells a lot about what Martian geology is like.
“Not only is it totally awesome to hear lasers pew-pewing on Mars, but we can also learn a lot about the properties of Martian rocks by listening to the change in acoustic signal as we shoot deeper and deeper with the laser,” Lanza tells Inverse.
What if Perseverance doesn’t find life on Mars?
Perseverance’s mission is our first real attempt at finding signs of life on another planet.
By Earth standards, Mars seemed to have had a habitable environment during its early history. Therefore, finding life on Mars would prove that life can begin and survive in conditions similar to the ones that created life on Earth.
However, if Perseverance doesn’t find signs of life, it provides an interesting conundrum whereby scientists have to rethink their long-held standards of habitability. It may take more than water and the right climate.
Perhaps life can survive in environments that are not similar to Earth, and maybe more extreme like Saturn’s moon Titan, or maybe life needs an extra ‘push’ to really begin on a planet and Earth happened to have that extra lucky push.