Earth’s toughest microbes could help humans live on Mars

Mars was not always the way it is today. Over billions of years, the planet lost the thick atmosphere that once helped protect its surface. What remains is an environment that looks nothing like what most Earth life can tolerate. The air is extremely thin and mostly carbon dioxide, the pressure is under one percent of Earth's, and temperatures swing from about -90°C (-130°F) up to 26°C (79°F).

On top of that, there is constant cosmic radiation and no breathable air. That means a Mars shelter has to do far more than provide a roof and walls. It must function as a life supporting refuge that can withstand a world built to break down living systems. Shipping large amounts of construction material from Earth would be far too expensive and unrealistic. A practical approach is to build with what is already on Mars. In situ resource utilization (ISRU) means using local materials, and it is central to any plan for sustainable human life on the Red Planet.

NASA's Perseverance rover has collected samples from Jezero Crater, an ancient Martian riverbed, and they may contain evidence of very early life. That possibility raises a bigger question that goes beyond searching for past biology. If microbes once lived on Mars, could microbial processes also help us build there?

From Earth's earliest life to Martian construction

Life on Earth began with simple microorganisms in shallow water environments. Over time, these tiny organisms reshaped the planet in enormous ways, including helping fill the atmosphere with oxygen and creating structures as durable as coral reefs. As we look toward Mars, researchers are asking whether small life forms could again play an outsized role, this time by helping turn a barren world into a place humans can survive.

Our research takes inspiration from natural systems and brings together experts from multiple fields in an international cross disciplinary effort. The focus is biomineralization, a process where microorganisms (bacteria, fungi, and microalgae) create minerals as part of their metabolism. Biomineralization has influenced Earth's landscapes for billions of years. Microorganisms that thrive in harsh settings such as acidic lakes, volcanic soils, and deep caves may be especially useful as we explore what could work under Martian conditions.

Turning Martian regolith into a building material

Using rover data about Martian soil (regolith), our team is examining different microbial mineralization routes to see which ones can produce strong materials for habitats while avoiding interplanetary pollution risks. The most promising option so far is biocementation. In this approach, microorganisms produce cement like substances such as calcium carbonate at room temperature.

A key part of the work centers on a partnership between two bacteria. One is Sporosarcina pasteurii, which is known for creating calcium carbonate through ureolysis. The other is Chroococcidiopsis, a tough cyanobacterium that can survive extreme environments, including simulated Martian conditions.

Together, they function as a cooperative system. Chroococcidiopsis releases oxygen, helping create a more supportive microenvironment for Sporosarcina pasteurii. It also produces an extracellular polymeric substance that can protect Sporosarcina pasteurii from damaging UV radiation on the Martian surface. In return, Sporosarcina secretes natural polymers that support mineral formation and help bind regolith. The result is that loose soil can be transformed into a solid, concrete like material.

3D printing habitats and supporting life systems

The long term vision is to combine this bacterial co culture with Martian regolith and use it as feedstock for 3D printing on Mars. This concept sits at the meeting point of astrobiology, geochemistry, material science, construction engineering, and robotics. If it works at scale, it could change how structures are designed and manufactured for the Red Planet.

The potential value is not limited to construction. Because Chroococcidiopsis can produce oxygen, it could contribute to both habitat stability and astronaut life support. Over longer periods, ammonia created as a metabolic byproduct of Sporosarcina pasteurii could help enable closed loop agricultural systems and might even play a role in Mars's terraforming efforts.

The next hurdles on the path to Mars homes

Even with promising ideas, the work is still at an early stage. International agencies aim to build the first human habitat on Mars in the 2040s, but recurring delays in Mars sample return limit how quickly Mars specific construction methods can be tested and confirmed. With space agencies planning crewed missions in the coming decade, research on bio derived construction needs to move forward now to be ready when humans arrive.

From an astrobiology standpoint, a major task is understanding how these microbial communities behave in Martian regolith and how they endure the planet's many stresses. Regolith simulants in laboratories provide a practical way to test co cultures in Mars like conditions and to build models that predict how well biocementation will perform.

Robotics adds another challenge. It is difficult to reproduce Martian gravity on Earth, yet gravity affects 3D printing and autonomous construction. To prepare for future missions, we need strong control algorithms and specialized protocols that let robotic systems build efficiently and reliably in Mars's unusual environment. Progress may be incremental, but every experiment, successful test, and refined procedure moves us closer to a future where humans can truly call Mars home.