Long-chain Hydrocarbons discovered on mars

Research suggests long-chain hydrocarbons, like decane and dodecane, were found on Mars, potentially indicating past life conditions.
The discovery was made by NASA’s Curiosity rover in a rock sample called “Cumberland” from Yellowknife Bay, analyzed using the Sample Analysis at Mars (SAM) instrument.
It seems likely these molecules could be remnants of fatty acids, essential for life, but the evidence leans toward non-biological origins as well, adding complexity to interpretations.

The Discovery

NASA’s Curiosity rover, exploring Mars since 2012, recently detected long-chain hydrocarbons in a rock sample named “Cumberland” from Yellowknife Bay in Gale Crater.

These molecules, including decane, undecane, and dodecane, are the largest organic compounds found on Mars to date, with carbon chains of 10, 11, and 12 atoms respectively.

This finding, reported in early 2025, suggests Mars may have had the chemical building blocks for life billions of years ago.

Significance and Interpretation

These hydrocarbons could be breakdown products of fatty acids, which are crucial for cell membranes in living organisms on Earth.

However, researchers acknowledge they might also form through non-biological processes, such as geological activity or meteorite impacts.

This dual possibility highlights the complexity of determining if Mars ever supported life, with ongoing debates in the scientific community.

Preservation Conditions

An unexpected aspect is how these large molecules survived Mars’ harsh conditions, including radiation and oxidation, for 3.7 billion years.

The preservation in mudstone from an ancient lakebed suggests Yellowknife Bay had a stable environment, possibly with liquid water for millions of years, which could have concentrated and protected organic molecules.

Background and Context

Mars has long been a focal point for astrobiology, given its proximity to Earth and evidence of past water activity.

The Curiosity rover, landing in Gale Crater in 2012, has been instrumental in analyzing Martian soil and rocks for signs of organic compounds, which are carbon-based molecules essential for life as we know it.

The recent discovery of long-chain hydrocarbons expands our understanding of Mars’ chemical history, particularly its potential habitability billions of years ago.

The rock sample, named “Cumberland,” was drilled from Yellowknife Bay, an area believed to be an ancient lakebed.

This location is significant because it suggests the presence of liquid water, a key ingredient for life, in Mars’ warmer, wetter past.

The Sample Analysis at Mars (SAM) instrument, a sophisticated laboratory on board Curiosity, was used to analyze the sample, heating it to release and identify organic molecules.

Methodology and Findings

The SAM instrument employs advanced gas chromatographic and mass spectrometric techniques to analyze Martian samples.

For Cumberland, the rock was heated twice, and the released gases were measured to detect the mass of molecules, identifying long-chain hydrocarbons.

The molecules found include:

Molecule	Carbon Atoms	Hydrogen Atoms
Decane	10	22
Undecane	11	24
Dodecane	12	26

These are known as alkanes, a type of hydrocarbon, and represent the largest organic molecules detected on Mars to date.

Researchers speculate these could be byproducts of fatty acids, such as undecanoic acid, dodecanoic acid, and tridecanoic acid, which are components of lipids found in cell membranes on Earth.

Implications for Past Life

The discovery is significant because fatty acids are fundamental to life, forming the structural basis of cell membranes in plants, animals, and microorganisms.

Caroline Freissinet, a research scientist involved in the study, stated, “Our study proves that even today, by analyzing Mars samples we could detect chemical signatures of past life, if it ever existed on Mars” (Universe Today).

This suggests that if life ever existed on Mars, we might find chemical evidence in its rocks.

However, the origin of these hydrocarbons remains debated. They could have formed through abiotic processes, such as geological activity or delivery by meteorites, rather than biological activity.

Monica Grady, a planetary scientist, noted, “This is an amazing result… If these are breakdown products from carboxylic acids, then we are seeing something very exciting indeed” (Science Magazine).

Yet, she also acknowledged the possibility of non-biological formation, adding complexity to the interpretation.

Challenging Assumptions

A common assumption is that Mars is a barren, lifeless planet, incapable of hosting complex organic compounds due to its harsh conditions, including radiation and oxidation.

This discovery challenges that notion, showing that large organic molecules can be preserved for billions of years.

The presence of these compounds in mudstone from an ancient lakebed suggests that Yellowknife Bay provided a stable environment, possibly with liquid water for millions of years, allowing organic molecules to concentrate and be preserved (Knowridge).

Daniel Glavin, a senior scientist at NASA’s Goddard Space Flight Center, emphasized, “There is evidence that liquid water existed in Gale Crater for millions of years and probably much longer, which means there was enough time for life-forming chemistry to happen in these crater-lake environments on Mars” (Knowridge).

This challenges the view that Mars was always inhospitable, suggesting a more dynamic past.

Preservation and Environmental Conditions

An unexpected detail is how these large molecules survived Mars’ harsh conditions. Radiation and oxidation typically destroy organic molecules over time, yet Cumberland’s molecules, with 11 to 13 carbon atoms, were preserved.

This preservation is attributed to the mudstone’s protective properties, formed in an ancient lake environment.

The finding supports the idea that organic molecules can survive Mars’ surface conditions, giving hope for future discoveries (Earth.com).

Future Directions and Missions

This discovery has implications for future Mars exploration, particularly NASA’s Perseverance rover, which is collecting samples for potential return to Earth.

Analyzing these samples in terrestrial laboratories could provide more detailed insights, potentially settling the debate about life on Mars.

Glavin stated, “We are ready to take the next big step and bring Mars samples home to our labs to settle the debate about life on Mars” (Earth.com).

The findings also guide future space exploration endeavors, opening new avenues for interplanetary science.

They contribute valuable insights into Martian history and potential habitability, informing missions aimed at unearthing signs of life beyond Earth (Bioengineer).

Conclusion

The detection of long-chain hydrocarbons on Mars is a significant milestone, suggesting the planet had the necessary ingredients for life to potentially emerge. While it does not confirm past life, it deepens our understanding of Mars’ chemical history and highlights the importance of continued exploration.

As we analyze more samples and refine our techniques, each discovery brings us closer to answering whether we are alone in the universe.