A group of scientists have just discovered the longest organic molecule seen on Mars, the fourth planet from the Sun, and an attractive field for humans to find life outside of Earth.
Mars is everywhere today, with obvious fluctuations in temperature, thin atmosphere and a clear lack of liquid water on the surface of the earth. However, according to new research published today in the Proceedings of the National Academy of Sciences, the macromolecules found on Mars are obviously as old as life on Earth, raising questions about the biological activities of ancient Martians.
Molecules are long carbon chains that contain up to 12 consecutive carbon atoms. These molecules sit on Mars for about 3.7 billion years and are not affected by geological activities, moisture or heat. Molecules are the same as the earliest signs of life on our planet.
Curiosity has inspired Mars for years, revealing new details of the ancient environment on Earth. The key to this environment is carbon, an element that is crucial to life and is useful for bonded molecules, including DNA and RNA. According to the release of the French National Center for Scientific Research (CNRS), the carbon chain “can exhibit characteristics similar to fatty acids produced on Earth through biological activity.”
The discovery of these organic molecules provides important insights into the potential biological processes of early Mars, but to be clear, this is not evidence of past or present life. However, it does tell us that what we know is the necessary components of life, and Mars once had the right conditions to support it.
“Although the source of these organic molecules on Mars could not be established in this study, these organizations could have either been formed by geoological processes on Mars (non-biological chemical reactions such as from hydrothermal activity), they were delivered to the surface of Mars from meteorites, or they are the organic remnants of an ancient martian biology,” said Daniel Glavin, a senior scientist for sample return at NASA's Goddard Space Flight Center and co-authored the paper in an email to Gizmodo.
The team, which includes scientists with CNR and several other institutions, conducted the findings using sample analysis from the MARS (SAM) laboratory. SAM contains a gas chromatograph and a mass spectrometer, which enables the identification of isolated molecules in samples collected by the rover station. Curiosity has seen organic matter in Martian mudstone before, but new research describes the longest chain found so far. Finding long carbon chains on Mars is important because it shows that NASA scientists are looking for signs of life, or at least the things that are life on Earth.
Curiosity is still strong, but in the mission of understanding Mars' ancient past, the successor is already on the way. ESA's EXOMARS mission will be launched in 2028, and the NASA-ESA MARS sample return mission will help scientists better evaluate Mars' compositions in ancient times and through proxy, which is the potential of ancient life on its surface.
“The discovery of long-chain hydrocarbons preserved in ancient sedimentary rocks on Mars (not completely destroyed by ionizing radiation exposure), which makes the current strategy of finding signs of ancient life in the near-face of Mars likely to have similar characteristics to life on Earth,” Glavin added. “Analysis of meteorites and samples from Osiris-Rex and Hayabusa2 missions. Shipped to Mars.”
“But the question of millions of dollars is: Is it necessary to transform from these basic chemical building blocks into the life that is needed for larger and more complex structures like proteins and nucleic acids found in cells?” Glavin added.
Liquid water once existed in a large number of reservoirs and lakes on Mars. Now long-dry, the Space Agency's roamers are tasked with exploring those once wet environments, seeking signs of primitive life, similar to those that exist in the earth's humid climate. Scientists have seen signs of liquid water beneath the surface of Mars, although such speculative discoveries will need to be said for scientists.
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Sam replica of NASA Goddard. Photo: Caroline Freissinet
In 2023, Perseverance Wanderers discover that organic molecules are retained on Mars, not confirming that life once existed on the Red Planet, but an encouraging indication of the conditions of living that we once knew.
The new approach could make it easier to find signs of life on Mars, perhaps explaining how life that might exist there disappeared as the Red Planet became barren and desolate.
In addition to Mars, the CNRS release notes that the same international team will build instruments like Sam for Dragonfly, a quad bike that will explore Saturn's moon Titans from the mid-2030s.
