Mars Regolith Helps Counter Earth Microbe Invasion; Tardigrade Experiments Give Hope for Life on Mars

Planet Mars appears to possess its own defence mechanism against life from Earth that could help shield the Red Planet from contamination by Earth microorganisms. Scientists led by Corien Bakermans, a professor of microbiology at Penn State University, conducted experiments by exposing tardigrades to Mars regolith simulants. The aim of the research was to determine how well tardigrades can adapt in regolith with the prospect of eventually turning Mars regolith into organic soil in which plants can grow.

Tardigrades are microscopic organisms that resemble chubby bears and are frequently nicknamed ‘water bears’. In the latest study, researchers from the United States, Poland, and the United Kingdom demonstrated how these creatures could assist future astronauts by surviving on Mars. The scientists explained that tardigrades can endure Mars regolith and help grow plants in a Mars greenhouse. The study shows how humans could use tardigrades to utilise extraterrestrial resources to support exploration on Mars or even other locations in the solar system. Additionally, the research may help protect astronauts from contaminants they carry.

The scientists replicated Mars regolith according to its chemical composition. Specifically, Bakermans and colleagues used two simulants based on NASA measurements from Gale Crater on Mars. One simulant, MGS-1, was designed to mimic the general properties of Mars regolith, while the OUCM-1 simulant represented the Rocknest area in Gale Crater.

The findings from Bakermans’ team were quite surprising. It turns out tardigrades have two life states, active and dormant. When exposed to MGS-1, tardigrades entered the dormant state in as little as two days. ‘We were surprised by how damaging MGS-1 was, so we theorise there may be something specific in the simulant that could be removed by washing,’ Bakermans said. When Bakermans’ team washed the MGS-1 samples and reintroduced a group of tardigrades, the results showed a mildly detrimental effect. However, the factors influencing the tardigrade life state have not yet been established. ‘That was unexpected, but in a sense it is positive because it means the regolith’s defence mechanisms can halt contamination,’ she added.

She continued that the washed MGS-1 layer could support plant growth or safeguard humans handling it. The results indicate that tardigrades could help future astronauts survive on Mars. These microscopic creatures could be useful for growing plants in regolith under closed greenhouse conditions. The findings are consistent with previous experiments demonstrating that Mars regolith is hazardous to active cells. On the other hand, the results bring a new finding that simply washing Mars regolith makes it much safer. This has implications for the hope that regolith could one day be turned into soil for growing plants, producing oxygen, and feeding astronauts living on Mars.

‘We are examining the potential resources to grow a planet as part of building a healthy community, but we are also studying whether there are intrinsic damaging conditions in regolith that can help protect against Earth contamination,’ Bakermans said. The findings were published in December 2025 in the International Journal of Astrobiology. However, Bakermans and colleagues emphasise that further research remains to be done to understand the feasibility of habitable conditions and hazards of Mars regolith. (EarthSky, Space.com/P-3)

NASA’s Curiosity rover has discovered a unique spider-web shaped geological formation on Mars. The boxwork phenomenon is believed to have formed from ancient water activity. The latest studies reveal that volcanoes on Mars have a far more complex eruption history than previously thought, driven by a magma system that continues to evolve. Elon Musk announced SpaceX has shifted focus to the Moon ahead of Mars, aiming for a self-sustaining city within ten years to safeguard humanity. Recent research reveals that Mars meteorite Black Beauty contains significantly more ancient water, strengthening evidence that Mars was once wet and habitable. Mars sits at an average distance of around 140 million miles or 225 million kilometres from Earth. That distance causes communication delays, limiting direct rover control.