The United States National Aeronautics and Space Administration’s (NASA) Perseverance rover has discovered evidence of organic compounds in a Martian crater, offering clues on the potential habitability of the planet, according to a new study.
Organic compounds are carbon-based molecules. Other elements, such as hydrogen, oxygen, nitrogen, phosphorus and sulphide, are often found in them.
Earlier, researchers had found a variety of organic chemicals with a Martian origin in meteorites sent from Mars as well as in Gale Crater. While earlier missions offered insightful data, the most recent research adds new evidence that deepens our understanding of Mars.
The results reveal that Mars has a more complex organic geochemical cycle than previously thought, implying the existence of multiple reservoirs of potential organic molecules on the planet.
The research featuring data from the rover was published in the journal Nature on July 12, 2023.
Notably, the study found molecules associated with aqueous processes, suggesting that water may have been a significant factor in Mars’s vast range of organic matter. The key building blocks necessary for life may have prevailed on Mars for a prolonged period than previously assumed.
“The potential detection of several organic carbon species on Mars has implications for understanding the carbon cycle on Mars, and the potential of the planet to host life throughout its history,” said Amy Williams, an assistant professor at the University of Florida’s Department of Geological Sciences.
Williams, an expert in organic geochemistry, was a part of the research team. She has been at the forefront of the quest for life on Mars.
Organic matter can be formed by a variety of biological and non-biological processes. These possible Martian organics could have originated from geological processes or chemical reactions, which can also produce organic molecules. The probable sources of these chemicals will be further investigated by Williams and her team.
Organic compounds can be created by processes not related to life, the study’s lead author Sunanda Sharma, a planetary scientist at the California Institute of Technology in Pasadena, told Space.com.
“As planetary scientists and astrobiologists, we are very careful with laying out claims — claiming that life is the source of organics or possible biosignatures is a last-resort hypothesis, meaning we would need to rule out any non-biological source of origin,” Sharma said.
So far, only the Mars Phoenix lander and the Curiosity rover have been able to detect organic carbon using cutting-edge methods like evolved gas analysis and gas chromatography-mass spectrometry.
The latest research presents an innovative approach that might also help locate basic chemical compounds on Mars — the scientists used an instrument called the Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals.
A high possibility for past habitability exists at the rover’s landing site in Jezero Crater: It has a variety of minerals, including carbonates, clays, and sulphates, due to its history as an old lake basin. Organic compounds and perhaps even traces of prehistoric life could be preserved by these minerals.
“We didn’t initially expect to detect these potential organics signatures in the Jezero crater floor,” Williams said. But their diversity and distribution in different units of the crater floor now suggest potentially different fates of carbon across these environments.