We May Be Missing Life on Mars
A team of international researchers co-led by a Cornell astrobiologist has suggested that the current state-of-the-art instrumentation being sent to Mars to collect and analyze evidence of ancient life on the planet may not be sensitive enough to make accurate assessments.
The researchers published a paper in Nature Communications on February 21, 2023, claiming that the detection of any organic material in Martian rocks could be difficult or impossible using current instruments and techniques.
To test their hypothesis, the team conducted experiments on sedimentary rocks found in the Red Stone Jurassic fossil delta of the Atacama Desert in Chile, which is considered an analog for Mars due to its geology.
Four instruments that are currently or will soon be on Mars were used in the study, and the researchers found that Red Stone samples showed a mix of biosignatures from current and ancient microorganisms that could only be barely detected with state-of-the-art laboratory equipment.
The study revealed that the instrumentation sent to Mars might not be sensitive enough to detect certain organic compounds depending on the instrument used, thus increasing the risk of obtaining false negatives in the search for life on Mars. The lead author of the paper, Armando Azua-Bustos, stressed the need for more powerful tools.
The researchers noted that in order to conclusively determine whether life ever existed on Mars, it is necessary to either put complex instrumentation on the planet or bring Martian samples to Earth. Both options are extremely challenging.
NASA is currently partnering with the European Space Agency and others to safely return Martian geological samples gathered by the Perseverance rover to Earth. The first European Mars rover, named Rosalind Franklin, is expected to launch as early as 2028 and carry a drill with the unprecedented capability of reaching down to a depth of 2 meters (6.5 feet) to analyze sediments better protected against the harsh conditions on the Martian surface.
The team consisted of researchers from institutions in Spain, Chile, Italy, France, and Japan, as well as scientists from Los Alamos National Laboratory in New Mexico, Georgetown University, and NASA’s Goddard Space Flight Center and Johnson Space Center.
The senior author of the paper, Alberto G. Fairén, is a visiting scientist at Cornell’s Department of Astronomy, a research professor at the Center of Astrobiology in Madrid, and also a member of the research team that conducted the study.
The researchers discovered that the Red Stone samples contained numerous microorganisms of undetermined classification, which they referred to as the “dark microbiome.”
The team’s findings suggest that the chances of detecting biosignatures of ancient life on Mars could be increased by analyzing deep samples from below the surface, where they may be better preserved.
Fairén emphasized that the decision of whether to analyze samples on the surface of Mars with limited instrumentation or to bring samples back to Earth for analysis with advanced instrumentation is a challenging one.
In addition to the challenges of analyzing Martian samples, the researchers highlighted the difficulty of developing instruments that are capable of detecting and analyzing organic material in harsh Martian conditions.
Despite these challenges, the study’s findings represent an important step forward in the ongoing search for evidence of ancient life on Mars and provide valuable insights into the limitations of current instrumentation and the need for continued research and development.
More information: Armando Azua-Bustos, Dark microbiome and extremely low organics in Atacama fossil delta unveil Mars life detection limits, Nature Communications (2023). DOI: 10.1038/s41467-023-36172-1. www.nature.com/articles/s41467-023-36172-1
