Surprisingly, a toxic compound found on Mars could help bacteria produce brick-like substances that could be used to assemble habitats on the Red Planet.

In 2025, researchers at the Indian Institute of Science showed how the bacterium Sporosarcina pasteurii, which is commonly found in Earth soils, could help create bricks out of regolith on the moon and Mars. The bacterium produces urea as a waste product, which can then react with calcium to produce calcium carbonate crystals. Then, by mixing these calcium carbonate crystals with guar gum, which is a natural adhesive extracted from guar beans, particles of the local regolith can be bound together to form a brick-like material.

The aim is to find ways to use in situ resources to build habitats in order to reduce the amount of heavy materials, such as cement, that would otherwise need to be shuttled to Mars from Earth.

"The idea is to do in situ resource utilization as much as possible," Shubhanshu Shukla, who is an astronaut with the Indian Space Research Organisation (ISRO) and a co-author of a new paper on the topic, said in a statement. "We don't have to carry anything from here; in situ, we can use those resources and make those structures, which will make it a lot easier to navigate and do sustained missions over a period of time."

Since samples of lunar regolith are rare and precious, and we have no samples of real Martian regolith, experiments use simulants instead — artificial regolith designed to be as close to the real deal as possible. However, for safety reasons, Martian simulants are missing one key ingredient: perchlorate, which is a toxic, chlorine-containing chemical first found in Martian regolith in 2008 by NASA's Phoenix lander, at an abundance of 0.5% to 1%.

But with regard to simulants, it's not perchlorate's toxicity that's the problem but rather its high flammability, and so usually it's left out.

When conducting their experiments, Shukla and his colleagues, led by microbiologist Swati Dubey of the University of Florida, had to carefully add perchlorate to a simulant called Mars Global Simulant 1, and then see how it affected Sporosarcina pasteurii's ability to produce material usable as bricks. Their experiment produced two main findings: one that was expected, and another that was very surprising.

Given perchlorate's toxicity, Dubey's team used a more robust strain of the bacterium found in soils near the Indian city of Bengaluru (a.k.a. Bangalore). As expected, the perchlorate affected the bacterium by causing stress to its cells, slowing the bacterium's growth and causing multiple bacteria to clump together. It also resulted in enhanced protein and molecule excretion, producing a material known as an extracellular matrix (ECM).

Despite the cellular damage to the bacterium, the team found that the brick material produced is stronger than in previous experiments, and Dubey thinks that it's all down to the ECM.

Using electron microscopy to study what was going on between the bacterium and the simulant, Dubey and her team found that more calcium chloride crystals were being formed, and that the ECM was forming tiny "microbridges" between bacterial cells and the crystals.

"When the effect of perchlorate on just the bacteria is studied in isolation, it is a stressful factor," Dubey said in the same statement. "But in the bricks, with the right ingredients in the mixture, perchlorate is helping."

Something about the composition of the bricks seems to be helping the bacterium — certainly without the guar gum and a catalyst in the form of nickel chloride, the bacterium doesn't see any benefit. Dubey thinks that the microbridges formed by the ECM could provide a pathway for nutrients to reach the bacteria, helping to repair their stressed cells and enhancing the bacteria's ability to bond the regolith particles into bricks — a process called biocementation.

Testing Dubey's hypothesis is the next step, and her team also wants to experiment with the biocementation process in a carbon dioxide-rich atmosphere, mimicking the atmosphere on Mars.

"Mars is an alien environment," said study co-author Aloke Kumar of the Indian Institute of Science. "What is going to be the effect of this new alien environment on Earth organisms is a very, very important scientific question that we have to answer."

The findings were published on Jan. 29 in the journal PLOS One.

Settling Mars has been a hot topic for years due to its close proximity and the similarities it shares with Earth like an atmosphere and water. Even NASA has set its sights on sending humans to Mars some time in the 2030s.

However, spaceflight is expensive, and getting people to a different world will carry a heavy price tag. Plus, if we’re able to send people to Mars, they’ll need tools and a place to stay. Sending such things over in a spacecraft would only add to the cost (by quite a bit, too).

So, rather than bring everything from Earth, scientists are exploring a different avenue of developing materials on Mars. New research from the Polytechnic University of Milan in Italy proposes a novel method — grow the materials on Mars itself. Using bacteria.

Building with bacteria

The idea of using found materials on missions to other planets — instead of just bringing everything with you from Earth — is called in-situ resource utilization (ISRU). "Harnessing local materials is the key to unlocking sustainable human presence on Mars," according to a statement.

The research proposes that biomineralization, a process that allows living organisms to produce minerals, could be used to create building materials once people get to Mars.

The two bacteriums that the paper singles out are Sporosarcina pasteurii and Chroococcidiopsis. By pairing these bacteriums together to create a "co-culture," the researchers think it may be possible to create a type of binding element that could be mixed in with regolith (rocks and dust) on the surface Mars.

"Sporosarcina secretes natural polymers that nurture mineral growth and strengthen regolith, turning loose soil into solid, concrete-like material," the spokesperson writes. "We envision this bacterial co-culture mixed with Martian regolith as feedstock for 3D printing on Mars."

Growing crops with bacteria

This process may allow future Mars settlers to grow the building materials they need to survive in the harsh environment. But the researchers envision more uses for the "microbial partnership" beyond Martian construction.

"Chroococcidiopsis, with its ability to produce oxygen, could support not just habitat integrity but also the life-support systems for astronauts," the spokesperson wrote.

"Over longer timescales, the ammonia produced as a metabolic byproduct of Sporosarcina pasteurii might be used to develop closed-loop agricultural systems and potentially help in Mars' terraforming efforts," they wrote.

The paper was published Dec. 2, 2025 in Frontiers.

Imagine a home on Mars. Is it filled with bacteria?

When we send humans to Mars, they'll need places to live. In a new study, a team of researchers from the Indian Institute of Science (IISc), in collaboration with India's space agency the Indian Space Research Organization (ISRO), suggest a new method to use bacteria to build these Martian habitats.

In this method, the team shows how "space bricks" for building a habitat on the Red Planet could be made with a combination of local Martian soil, bacteria and urea, a waste compound eliminated through urine by mammals.

Related: Newly discovered bacteria on space station could help astronauts grow plants on Mars

To make these Red Planet "space bricks," the team mixed together a "slurry" of simulated Martian soil made out of guar gum, which is a product of processed guar beans, combined with urea, the chemical nickel chloride and the bacterium Sporosarcina pasteurii. This mixture is blended together and can be poured into molds of any shape. 

Previously, this team had tried to make "space bricks" with simulated lunar soil, but they were only able to make cylinder-shaped bricks, whereas, with their new Martian method in which they harden a "slurry" mix in a mold, they can make bricks of any shape, according to a statement.

After a few days in the mold, a chemical reaction transforms the "slurry" into a solid "space brick." Within the mixture, the bacteria and urea interact, causing the urea to crystallize and form crystals of calcium carbonate, a chemical compound that is often taken as a nutritional calcium supplement but which also makes up biological structures like shellfish skeletons and eggshells. The crystals come together with biopolymers, which are natural polymers produced by the bacteria, and the combination forms a sort of cement that holds the particles of the simulated Martian soil together.

The team added the nickel chloride to the mixture after determining that the compound made it easier for the bacteria to grow in the "soil" mixture.

"Martian soil contains a lot of iron, which causes toxicity to organisms," co-author Aloke Kumas, an associate professor in the department of mechanical engineering at IISc, said in a statement. "In the beginning, our bacteria did not grow at all. Adding nickel chloride was the key step in making the soil hospitable to the bacteria."

With the new method, the team was able to successfully make "space bricks," but the researchers still have a lot of testing to do before such a technique is used on the Red Planet. The scientists plan to study how the bricks would respond to the Martian environment, particularly the planet's very thin, primarily carbon dioxide atmosphere, as well as the much reduced gravity. 

According to the statement, the team plans to test their bricks in a device called the Martian Atmosphere Simulator (MARS), that the researchers have said will recreate Martian atmospheric conditions in a controlled laboratory setting. The team has additionally developed a microchip device to measure and study bacterial activity in space, according to the same statement. 

One concern that this study doesn't address is planetary protection, the concern of contaminating the Earth. Scientists have to ensure that spacecraft missions will not carry any unintended bacteria or other contaminants that could cloud scientific findings or damage the world itself. (Planetary protection likewise requires measures to prevent a spacecraft bringing anything unintended back home to Earth.)

It is yet to be seen how a method like the one described in this study might work within planetary protection guidelines, which are especially stringent on Mars, where spacecraft like NASA's Perseverance rover are actively looking for evidence of past microscopic life.

This work is described in a study published April 14 in the journal PLOS One.

Email Chelsea Gohd at cgohd@space.com or follow her on Twitter @chelsea_gohd. Follow us on Twitter @Spacedotcom and on Facebook.

Could humanity's future on Mars be built on a foundation of … bacteria?

Before we send humans to the Red Planet, it might be a good idea to send bacteria first. In his dissertation, Benjamin Lehner, a doctoral candidate at Delft University of Technology in the Netherlands, suggested that we send bacteria to Mars that can mine usable iron out of the Martian soil. Specifically, he suggested that we send the bacterial species Shewanella oneidensis. 

"In its natural form, we can't use much of the iron in the Martian soil," Lehner said in a statement. "But S. oneidensis has the ability to turn part of the soil into magnetite, a magnetic oxide of iron."

Related: Just Like Home: Space Station Has Same Microbes As Your House 

In his dissertation, Lehner suggested that, ahead of humans expeditions to Mars, we send a crewless capsule containing a rover, a bioreactor and a 3D printer. The rover would roll around on the planet, scooping up Martian soil, or regolith, which is naturally iron-rich. Then, the robot would bring the soil back to the bioreactor, which would be filled with this bacteria. 

The bacteria would then get to work, producing magnetite from the regolith. The magnetite would then be extracted and separated from the rest of the soil with magnets. Finally, the 3D printer would turn this raw metal material into a host of valuable parts for humans. The printer could create screws, nuts, bolts or any other building piece that could be integral to building human housing on Mars.

But how much iron could this process realistically produce? Lehner and his team said a 1,400-liter (370 gallons) reactor could produce about 350 kilograms (770 lbs.) of the material every year. "After 3.3 years, it would produce more iron than can fit inside the capsule," he said in the statement. "By sending several of these unmanned modules to Mars, we can produce a good amount of iron in a few years' time."

In addition to preparing Mars for the arrival of its first humans, missions and methods like this could also be a key asset in our species' continued existence on the Red Planet. If things break on a planet many millions of miles away from Earth, it likely won't be possible to simply order a replacement. So sustainable solutions such as this will be critical. 

This idea takes into consideration both the harsh conditions on the Martian surface and the financial and weight constraints on sending anything to Mars. Bacteria are self-reproducing, virtually weightless, cheap to transport and often able to withstand high radiation. The only thing? They need to eat something. 

Lehner proposed that microalgae be sent along with the bacteria to provide a sustainable source of food. Microalgae can take care of themselves, surviving on sunlight and CO2, which they will turn into nutrients and oxygen for the bacteria. The residual waste left behind by this microalgae (in addition to organic waste from the bioreactor) could also serve as compost for future Mars-bound astronauts, Lehner said in the statement.

Lehner said another issue cropped up in developing this proposal: the possible contamination of Mars with Earth bacteria. "We want to prevent our bacteria from contaminating the planet, since that could hinder the search for life on Mars," Lehner said in the statement. To safeguard against that, Lehner's team suggested that the iron material produced be stored safely in an inflatable sealed chamber attached to the side of the capsule. 

• How to Keep Spacesuits Germ-Free on Mars 
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• There's Drug-Resistant Bacteria in the Space Toilets, Guys

Follow Chelsea Gohd on Twitter @chelsea_gohd. Follow us on Twitter @Spacedotcom and on Facebook.

Marsquakes — that is, earthquakes on Mars — could generate enough hydrogen to support life there, a new study finds.

Humans and most animals, plants and fungi get their energy mainly from chemical reactions between oxygen and organic compounds such as sugars. However, microbes depend on a wide array of different reactions for energy; for instance, reactions between oxygen and hydrogen gas help bacteria called hydrogenotrophs survive deep underground on Earth, and previous research suggested that such reactions may have even powered the earliest life on Earth.

Prior work suggested that when rocks fracture and grind together during earthquakes on Earth, silicon in those rocks can react with water to generate hydrogen gas. Study lead author Sean McMahon, a geomicrobiologist at Yale University, and his colleagues wanted to see if marsquakes could generate enough hydrogen to support any microbes that might potentially live on the Red Planet. [The Search for Life on Mars in Pictures]

"These findings were surprising and exciting because we didn't know if we were going to find anything at all," McMahon said.

The researchers said the hydrogen gas in the samples they analyzed was abundant enough to support hydrogenotrophs on Earth.

"Our findings are a contribution to a broader picture of how geological processes can support microbial life in extreme environments," McMahon told Space.com. "There's not much of what we think of as food miles below Earth's surface, but over the last few decades, scientists have found that Earth has a huge amount of biomass down there, maybe 20 percent or more of Earth's biomass."

When it comes to whether marsquakes and water might work together to generate hydrogen on Mars, previous research suggested that liquid water was once abundant on the surface of Mars. It also suggests that large reserves of liquid water may still exist underground on the Red Planet at depths of about 3 miles (5 kilometers) on average. However, Mars has much fewer quakes than Earth, because the Red Planet nowadays lacks both volcanism and plate tectonics.

Still, the researchers noted that conservative models of marsquakes based off data from NASA's Mars Global Surveyor suggest that, on average, the Red Planet experiences a magnitude-2 event every 34 days and a magnitude-7 event every 4,500 years. This means that marsquakes may on average generate less than 11 tons (10 metric tons) of hydrogen annually over the whole of Mars, which may be still enough to sporadically fuel pockets of microbial activity there, the researchers said. [The Biggest Earthquakes in History]

"This hydrogen can probably support only small amounts of biomass," McMahon said. "Still, this fits into the growing picture of the kind of biosphere that Mars might be capable of sustaining. If you look at bacteria and other microorganisms on Earth, you find ones capable of resting in a dormant state for extremely long periods of time, and they can wake up and reproduce and then go back to sleep again for another 10,000 years or so."

McMahon noted that even rocks that lack water can apparently generate hydrogen gas during earthquakes. This suggests that grinding might release hydrogen that is ordinarily chemically bound to rocks. "A lot of work needs to be done to understand how hydrogen can be liberated," he said.

NASA's 2018 InSight mission is scheduled to measure seismic activity on Mars. "Having actual data of marsquakes from the surface of Mars will show whether what we've done here is really relevant or not," McMahon said.

McMahon and his colleagues John Parnell at the University of Aberdeen in Scotland and Nigel Blamey of Brock University in Canada detailed their findings in the September issue of the journal Astrobiology.

Follow Charles Q. Choi on Twitter @cqchoi. Follow us @Spacedotcom, Facebookand Google+. Original article on Space.com.