NASA may have evidence of ancient life on Mars. Will it be able to recover samples?

On Mars, inside a tube for storing samples, there is a rock dotted with spots resembling tiger skin, which may contain evidence of the existence of life in the past, outside planet Earth. NASA's Perseverance probe collected the sample, called "Sapphire Canyon," from rocky outcrops at the edges of the Neretva Valley, which was carved by rivers that flowed into an ancient lake inside Jezero Crater, more than 3 billion years ago.

The probe landed at the bottom of the dry lake in February 2021, searching for rocks that were formed by water or changed over time, because they are likely the best able to preserve evidence of the existence of life. The Perseverance probe's science team said the Sapphire Canyon sample, about the size of a piece of chalk, represents the type of rock scientists were hoping to find.

Adrian Broz, a researcher at Purdue University and a member of the team, said it is the first time that what meets the criteria for a “potential biosignature” has been found on Mars. He added that the sample is stored inside the probe, waiting to be returned to Earth.

However, the sample's arrival to Earth may be delayed after NASA canceled in 2024 a joint program with the European Space Agency to return it, due to its high cost and complexity, despite spending billions of dollars on it, with no clear alternative yet. NASA told Ofoq News in July that it was looking for simpler and less expensive options, including commercial or international contributions, without announcing a final plan.

Although the Sapphire Canyon sample strengthens the potential evidence for the presence of ancient microbial life on Mars, concluding the matter requires analyzing it on Earth. Bruni Horgan, professor of Earth, atmospheric and planetary sciences at Purdue University, explained that the probe, which cost about $2.4 billion, does not have the tools necessary to answer these questions on its own.

“We won't know the truth until the samples are returned to Earth,” Horgan said, which could reveal whether life is common in the universe or whether Earth is unique. On the other hand, China seeks to return samples from Mars by 2031, through the “Tianwen-3” mission expected to be launched in 2028.

These samples may differ from those collected by Perseverance, which may reveal new evidence of the existence of life on the Red Planet. 'Holy Grail' for scientists The Sapphire Canyon sample is important because of its mottled spots, which resemble those formed on Earth in soil and sediments by microbial activity, and are known as "reaction fronts" or "reduction spots." “When organic matter is buried in soil or sediment, microbes break it down, forming faint halos and spots similar to those observed by Perseverance in an ancient river valley on Mars,” said Adrian Broz, co-author of a study on the sample published in September 2025.

The Perseverance probe extracted the Sapphire Canyon sample from the Chiava Falls rock in July 2024, amid hundreds of thousands of spots that may have been formed by ancient microscopic organisms. But determining whether these signs are evidence of the existence of past life requires returning the samples to Earth, to rule out non-biological chemical and geological processes.

The Martian meteorite "Allan Hills 84001", which was found in Antarctica in 1984, had previously raised hopes of discovering ancient life, before it became clear that its effects resulted from non-vital geological processes. Ashwin Vasavada, responsible for the Curiosity probe project at NASA, said that determining the existence of ancient life requires multiple analyzes in the best laboratories, which is capabilities that Perseverance does not have.

Melissa Rice, professor of planetary sciences at Western Washington University, explained that the probe's tools were designed to explore rocks, select samples, and determine their geological characteristics in preparation for returning them to Earth. NASA's first requests to fund studies to return Mars samples date back to 1978, after the Viking missions to search for evidence of life on the red planet.

This reflects that this scientific goal has remained elusive for decades, said Casey Dreyer, head of the Space Policy Division at the Planetary Society. A scientific survey conducted in 2003 and subsequent reports identified returning samples from Mars as a major priority for future space missions, linking the sample return program to the Perseverance probe mission.

A complex path The original plan, revealed in 2020, included sending a rover to Mars to collect samples, and another to return them to Earth by 2031, at the earliest. The ascent vehicle would have released a container the size of a football carrying the samples, to be picked up by a European rover orbiting Mars.

The European spacecraft would then return to Earth, transfer the sample container to another vehicle that would separate from it and land the samples safely on our planet. In 2022, the plan was modified so that Perseverance would deliver the samples to an ascent vehicle for its return journey.

The lander was also scheduled to carry two small helicopters to collect samples from the probe if it was unable to reach the landing site. This amendment postponed the date for returning the samples to the year 2033.

Independent review committees have warned of the complexity of the sample return mission, after its budget increased to $11 billion and was postponed to 2040, amid NASA budget cuts and declining political support for the project. In January 2025, the agency put forward two faster and less expensive options, relying on commercial partnerships or technologies previously used to land on Mars, weeks before Donald Trump assumed the presidency and searched for a new NASA director.

NASA's 2026 budget request came as a surprise, as the agency announced its intention to end the sample return program due to its high cost, noting the possibility of returning them via future missions to Mars. The program was absent from the 2027 budget request, after NASA spent about $2.5 billion on it, according to Dreyer.

NASA Administrator Jared Isaacman has expressed interest in returning Perseverance samples to Earth. Isaacman said that returning Mars samples could achieve “the most important scientific breakthrough in human history,” whether through robots or astronauts, without specifying a date, holding the previous administration responsible for canceling the program because of its cost, which would have exceeded the cost of an aircraft carrier.

Despite the controversy over the fate of the program, no new details about the next steps were announced. China enters the race For its part, China is preparing to return samples from Mars through the “Tianwen-3” mission, benefiting from the success of the “Chang’e-6” mission in 2024, which returned the first samples from the far side of the moon.

The plan includes a lander equipped with an ascent vehicle and a helicopter, and an orbital vehicle to transport samples to Earth. The lander will dig up to two meters deep in search of evidence of life, while the helicopter collects rock samples.

China plans to operate the lander for about 70 days. Scientists are examining 86 potential sites in search of traces of liquid water and ancient microbial activity, focusing on samples rich in iron oxides and watery clay, as they may contain traces of ancient cells and organic molecules.

A ray of hope: Scientists still hope to return Perseverance samples to Earth thanks to the efforts of private sector companies, according to Horgan. Whitley Poeser, director of the Exploration Missions Division at Lockheed Martin, said that the company, based on its experience in Mars and sample return missions in cooperation with NASA, has developed a simplified plan to collect samples left by the probe on the surface of the planet.

Martin proposes to return 30 samples from Mars to Earth, at a cost of less than $3 billion, by 2037, using vehicles and technologies she developed on previous space missions. The company confirmed its readiness to implement the plan if given the opportunity.

Rice said that Mars samples may reveal what Earth's rocks cannot, after erosion and other factors changed their nature over time, noting the importance of educating the public about how close scientists are to answering major questions about life. She added: “We will continue to advocate for the return of samples, to ensure people understand how close we are to answering these questions.

The rocks are in their tubes and ready, all we have to do is go get them.”