UNIVERSITY PARK, Pa. — In a groundbreaking study, researchers from NASA Goddard Space Flight Center and Penn State have suggested that ancient microbes or their remains could be preserved in Martian ice deposits. By simulating Martian conditions in a laboratory setting, the team demonstrated that fragments of protein molecules from E. coli bacteria could remain intact for over 50 million years, despite the harsh cosmic radiation on Mars. This discovery, published in the journal Astrobiology, encourages future Mars missions to focus on pure ice or ice-dominated permafrost rather than rocks, clay, or soil.
“Fifty million years is far greater than the expected age for some current surface ice deposits on Mars, which are often less than two million years old, meaning any organic life present within the ice would be preserved,” said Christopher House, a co-author of the study and professor of geosciences at Penn State. “That means if there are bacteria near the surface of Mars, future missions can find it.”
Simulating Martian Conditions
The research team, led by Alexander Pavlov, a space scientist at NASA Goddard, conducted experiments by suspending E. coli bacteria in test tubes with solutions of pure water ice. Other samples were mixed with water and Mars-like sediment, including silicate-based rocks and clay. These samples were frozen and exposed to radiation equivalent to 20 million years of cosmic ray exposure on Mars, followed by an additional simulation of 30 million years.
In pure water ice, more than 10% of the amino acids from the E. coli samples survived the simulated 50-million-year timespan. In contrast, samples containing Mars-like sediment degraded ten times faster and did not survive. A 2022 study by the same group had found that amino acids preserved in a 10% water ice and 90% Martian soil mixture were destroyed more rapidly.
“Based on the 2022 study findings, it was thought that organic material in ice or water alone would be destroyed even more rapidly than the 10% water mixture,” Pavlov said. “So, it was surprising to find that the organic materials placed in water ice alone are destroyed at a much slower rate than the samples containing water and soil.”
Implications for Future Mars Missions
The study’s findings suggest that pure ice or ice-dominated regions on Mars are ideal locations for searching for recent biological material. This insight could significantly influence the design and focus of future Mars missions. The 2008 NASA Mars Phoenix mission was a pioneer in excavating and capturing images of ice in the Martian equivalent of the Arctic Circle, highlighting the potential of ice-rich areas for exploration.
“There is a lot of ice on Mars, but most of it is just below the surface,” House noted. “Future missions need a large enough drill or a powerful scoop to access it, similar to the design and capabilities of Phoenix.”
Broader Implications for Astrobiology
In addition to Mars, the researchers also tested organic material under conditions similar to those on Europa, Jupiter’s icy moon, and Enceladus, Saturn’s icy moon. They found that even colder temperatures on these moons further reduced the rate of organic material deterioration. These results are encouraging for NASA’s Europa Clipper mission, which aims to explore Europa’s ice shell and ocean to assess potential habitability.
The research underscores the importance of federal funding in driving scientific innovation. NASA’s Planetary Science Division Internal Scientist Funding Program supported this study, highlighting the critical role of federal support in advancing our understanding of the cosmos.
As researchers continue to solve real-world problems, the implications of federal funding cuts threaten to slow progress. The ongoing support for scientific research is vital for maintaining the United States’ competitive edge and ensuring a robust economy.
