Why Mars? The fascination with exploring the red planet

The mystique of Mars is one that humans can’t seem to resist. The red planet has easily captured our interest for centuries, heavily featured in science fiction books and films and the subject of robotic exploration since the 1960s.

In February, three spacecraft arrived at Mars after departing from different launch points on Earth in July. These myriad missions seek to understand our planetary neighbor and unlock the secrets of its past to prepare for future exploration.

The three missions – China’s Tianwen-1, the United Arab Emirates’ Hope Probe and NASA’s Perseverance rover – took advantage of an alignment between Mars and Earth that occurs every 26 months, allowing for quicker and more efficient trips when the two planets are on the same side of the sun.

The Hope Probe will stay in orbit for a Martian year – equivalent to 687 days on Earth – to gather data about Mars’ atmosphere.

Tianwen-1, whose name means “Quest for Heavenly Truth,” is orbiting the planet before landing a rover on the surface, with the hope that it can gather important information about the Martian soil, geological structure, environment, atmosphere and signs of water.

The Perseverance rover is searching for signs of ancient life on Mars and will collect samples to be returned to Earth by future missions.

NASA's Perseverance Mars rover took a selfie with the Ingenuity helicopter, seen here about 13 feet (3.9 meters) from the rover. This image was taken by the WASTON camera on the rover's robotic arm on April 6, 2021, the 46th Martian day, or sol, of the mission. Credit: Credit: NASA/JPL-Caltech/MSSS

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Perseverance also carries the names of nearly 11 million people etched on three silicon chips. She is a robotic scientist exploring Mars on behalf of humanity and is able to share what she sees and hears through 23 cameras, including video, and two microphones.

If three missions arriving at Mars within days of each other seems excessive, imagine explorers seeing Earth for the first time and wanting to understand all aspects of its past, climate, water, geology and life systems. It takes time and different capabilities to explore aspects of an entire planet to know the real story.

Martian intrigues

Even though Mars is millions of miles away, it’s still visible in our night sky from time to time. It’s easy to imagine orbiters whirling around the planet or rovers embedding wheel tracks in the red dirt.

The next step is imagining humans stepping on the surface of Mars to explore with their own eyes what has only been a reality for robotic explorers.

NASA's Curiosity Mars rover used two cameras to create this selfie in front of Mont Mercou, a rock outcrop that stands 20 feet (6 meters) tall. Image Credit: NASA/JPL-Caltech/MSSS

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NASA has been sending missions to explore Mars since 1965, sharing images and knowledge gained about our fascinating neighbor. Mars is the second most accessible place in our solar system to send missions beyond the moon.

But it also has a mysterious history, and it may have once been a lot like Earth – meaning it’s a great place to search for ancient life. And many of the key questions we have about the solar system can be addressed by studying Mars.

“Mars is the most Earth-like planet in our solar system,” said acting NASA administrator Steve Jurczyk. “That’s really intriguing because by studying the geological and climate history of the planet and how it evolved, we can also inform how Earth has evolved and how it will evolve in the future.”

The capable robots exploring Mars now lay the groundwork for landing human missions on the red planet later, Jurczyk said.

For the longest time, scientists thought Mars was always a dry, cold and desolate place, he said. But orbiters and rovers have provided evidence of when Mars was warmer and wetter billions of years ago.

Combining two images, this mosaic shows a close-up view of the rock target named "Yeehgo" from the SuperCam instrument on NASA's Perseverance rover on Mars. The component images were taken by SuperCam's Remote Micro-Imager (RMI) on March 7, 2021 (the 16th Martian day, or sol, of Perseverance's mission on Mars). To be compatible with the rover's software, "Yeehgo" is an alternative spelling of "Yéigo," the Navajo word for diligent.

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In 1994, NASA began the Mars Exploration Program with the goals of exploring the red planet to understand the formation and evolution of Mars, its potential to have once hosted life and as a site of exploration by humans.

Remaining at Mars feeds a continuous cycle of information based on observations gathered by orbiters from above and robots on the surface.

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At NASA, efforts are underway to land the first woman and the next man on at the lunar south pole by 2024 through the agency’s Artemis program. The moon is viewed as a proving ground for strategies and technologies before going on to Mars.

Along with Perseverance, NASA also sent Ingenuity, which will soon be the first helicopter to fly on another planet. The four-pound technology demonstration is an experiment for powered and controlled flight in the thin atmosphere of Mars.

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Sojourner, the microwave-sized rover that landed on Mars in 1997, was a technology demonstration. Its success led to NASA’s larger rovers such as Curiosity and Perseverance. Ingenuity could be the first of many rotorcraft that may act as scouts for rovers and astronauts, flying over dangerous or inaccessible terrain.

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“In both science fiction and the real world, the future belongs to robots and humans working together, each contributing their unique capabilities in truly ingenious ways exploring the universe,” wrote Robin Murphy in a recent Focus article for the journal Science Robotics. Murphy is the Raytheon Professor in Computer Science & Engineering at Texas A&M University.

Bringing Mars to Earth

The Perseverance rover is exploring Jezero Crater, the site of an ancient lake bed and river delta that existed 3.9 billion years ago when Mars was potentially habitable for life. The rover is searching for evidence of microfossils and will collect samples from various parts of the lake bed and river delta in the hopes of finding them.

They will be the first samples from Mars ever returned to Earth, but the route is complicated.

The Mars Sample Return mission involves NASA collaborating with the European Space Agency. And given the difficulty of this multipronged return journey of the samples, they won’t land on Earth until 2031, at the earliest.

In this illustration, the Perseverance rover uses its drill to core a rock sample on Mars.

In 2026, NASA and ESA will launch the Mars Ascent Vehicle lander and rocket carrying the Sample Fetch Rover. Perseverance will witness and share images of the landing of this spacecraft on Mars when it occurs in 2028 – a first.

An illustration of NASA?s Perseverance rover exploring inside Mars? Jezero Crater. The 28-mile-wide (45-kilometer-wide) crater is located on the western edge of a flat plain called Isidis Planitia, which lies just north of the Martian equator. NASA believes the ancient lake-delta system there is the best place for Perseverance, in its hunt for signs of past microscopic life, to find and collect promising rock and regolith (broken rock and dust) samples for a possible future return to Earth.

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The lander will release the fetch rover on the Martian surface to collect the samples and return them to the lander. The samples will be transferred to the ascent vehicle, and it will blast off from the surface of Mars – another first that will be witnessed by Perseverance.

The ascent vehicle will rendezvous with an ESA spacecraft orbiting Mars and shoot out a football-size container holding the samples. The ESA orbiter will capture the container during this pass between spacecrafts and head back toward Earth. Close to Earth, a NASA payload on the orbiter will put the container of samples in an entry vehicle that can be deployed from the orbiter and land the samples on Earth in 2031.

A rocket will carry a container of tubes with Martian rock and soil samples into orbit around Mars and release it for pick up by another spacecraft.

The samples will land in Utah and be transported to a type of facility usually associated with the handling of biohazards. Then, scientists from around the world will be able to study and analyze the chemical and physical properties of these rock and soil samples for Mars, searching for signs of past life.

Members of NASA's Perseverance rover team react in mission control after receiving confirmation the spacecraft successfully touched down on Mars, Thursday, Feb. 18, 2021, at NASA's Jet Propulsion Laboratory in Pasadena, California. 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. Photo Credit: (NASA/Bill Ingalls)

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“Because of its extensive laboratory suite, the Perseverance robot has a real chance of detecting signs of life on Mars,” wrote Neil Jacobstein in a recent Focus article for Science Robotics. Jacobstein is a mediaX Distinguished Visiting Scholar at Stanford University and the chairman of the Artificial Intelligence and Robotics Track at Singularity University, a US-based company offering educational programs.

“If it does detect life or microfossils and if that discovery is verified by subsequent missions, it will alter our understanding of the universe. Those that believe that Earth is the sole cradle of life will have to adjust their horizons. Those that think life may be ubiquitous in the universe will have a new and microscopic start for their expanding inventory of life. Either way, robots will have proven to be a central and enduring component of space exploration.”