“Unraveling the Mysteries of Mars: A Quest for Cosmic Significance”

Tech magnate Elon Musk is steadfast in his goal to create a self-reliant human community on Mars and is currently advancing technologies to realize this ambition. 

It is a captivating possibility, and if realized, humans might only be able to endure in some form of biodome. Yet this once again prompts the inquiry: What do we truly comprehend about Mars’ capacity to sustain life forms in general? 

What insights does scientific research provide on this matter? This question has captivated researchers for many years. 

Since the Mariner 4 flyby back in 1965, over 40 missions have been initiated to investigate Mars.  

These endeavors – including orbiters, landers, and rovers – strive to chart the planet’s terrain, analyze its atmosphere, seek out water, and examine the likelihood of life. 

But what makes Mars so captivating? Why does it stand out as a focal point in the quest for extraterrestrial existence? 

The quest for life: bioindicators and biosignatures 

Astrobiology, the scientific exploration of life throughout the universe, attempts to resolve one of humanity’s most ancient queries: Are we solitary?  

In contrast to the extraterrestrial fantasies portrayed in science fiction, astrobiology employs empirical methods to investigate the possibility of life existing beyond our planet. 

This discipline utilizes Earth’s example, the only recognized model of life, to explore other environments that could potentially foster life. However, life forms present on primitive Earth or other celestial bodies could have varied tremendously, adding layers of complexity to the investigation. 

Researchers seek life beyond Earth by pinpointing environments akin to those that promote life here, concentrating on the presence of liquid water, organic substances, and energy. 

Although the discovery of organic compounds might offer fascinating hints, it does not confirm life, as these molecules can also originate from non-biological mechanisms.

Researchers emphasize two key concepts: 

Bioindicators: Indicators of possible life that might also result from non-biological phenomena, such as amino acids, which occur in living beings but are also detected in meteorites.  

While their discovery suggests possible biological activity, it does not constitute definitive proof. 

Biosignatures: Distinctive markers of life, including DNA, biogenic minerals (e.g., fossils), or homochirality – the exclusive occurrence of one molecular arrangement (e.g., left-handed amino acids in Earth life). Encountering such characteristics in extraterrestrial substances would strongly imply biological origins. 

This differentiation highlights the challenges and intricacies involved in identifying life beyond our planet. 

The history of Mars: a narrative of two realms 

Today, Mars is a frigid, barren, and unfriendly environment with an average temperature of -55°C. Its sparse atmosphere offers minimal shielding against harmful radiation, including ultraviolet light.  

Reactive oxidants found in the soil, such as perchlorates, can break down organics, while radiation exposure further deteriorates them over time, complicating detection efforts. The planet’s severe environment presents a significant hurdle to the preservation of organic compounds. 

Nevertheless, billions of years ago, Mars featured a more humid and temperate climate.  

Evidence of ancient rivers, lakes, and deltas indicates that water once traversed its surface.  

Early Mars likely exhibited conditions akin to those on primordial Earth, with water and organic materials possibly facilitating prebiotic chemistry. 

This positions Mars as a key candidate for examining the possibility of past habitability. 

Organic compounds: hintsfrom intrigue 

Nasa’s Curiosity rover achieved a milestone in 2018, discovering intricate organic matter in rocks aged three billion years located in Gale Crater.  

These substances – fundamental elements of life – could have developed through biological processes or via abiotic mechanisms. 

Curiosity has detected trace amounts of substances such as methane, chlorinated compounds, sulfur-containing materials, and lengthy hydrocarbons.  

Nonetheless, their source is still ambiguous, as organic materials might originate from non-biotic events, including comets, meteorites, hydrothermal processes, or light-driven chemical reactions within Mars’ atmosphere. 

The oxidizing environment on Mars poses challenges for the preservation and identification of these substances, necessitating meticulous analysis of the results. 

Obstacles in identifying life 

The unforgiving Martian environment imposes considerable barriers to finding life.

Perchlorates present in the soil decompose organic substances during examination, complicating the efforts of instruments like Curiosity’s Sample Analysis at Mars (SAM) suite in recognizing them. 

Furthermore, prolonged exposure to radiation over billions of years deteriorates organics, lowering the chances of discovering well-conserved traces on the surface. 

Future missions are set to tackle these difficulties. 

For instance, in 2029, the European Space Agency’s Rosalind Franklin rover intends to drill down to 2 meters below the surface, where organic compounds may be protected from radiation and preserved more effectively. 

It will come equipped with multiple instruments, including one specifically for examining the broadest possible range of organic compounds. 

The Mars Organic Molecules Analyzer (MOMA) is a streamlined tool designed to identify and analyze organic substances on Mars. 

Utilizing a desorption laser, it vaporizes molecules from surface or subsurface samples, which are then identified with a mass spectrometer by comparing their chemical structures to a reference database. 

This approach is efficient but primarily focuses on surface molecules and may struggle to distinguish between simultaneous identifications. 

It’s akin to counting cows, sheep, and goats all together. The optimal way would be to categorize each species and count them separately.  

Gas chromatography complements the laser analysis by heating the entire sample to release volatile compounds, separating them through chromatography, and identifying each substance individually using the mass spectrometer. 

Additionally, samples can undergo chemical transformation to isolate chiral variations of molecules. A notable overabundance of one chiral variant or homochirality would serve as a strong biosignature, indicating the potential for Martian life. 

Why Mars? The wider ramifications 

Mars is a prominent contender in the quest for extraterrestrial life due to its historical water flow, existence of organic compounds, and closeness to Earth. 

This exploration is motivated by more than mere intrigue; it aims to comprehend humanity’s role in the cosmos. 

Is existence exclusive to Earth? And is it so unique that it can only thrive on our planet?  

In addition to Elon Musk’s endeavors to transform Mars into a habitable place for humans, scientists are examining whether it was ever inhabited.  

Uncovering life on Mars, whether in the past or present, would imply that life might be prevalent in the universe, while confirming that Mars has never supported life could suggest its rarity. 

Regardless of the outcome, every discovery on Mars enriches our comprehension of planetary development and livability, contributing to the resolution of that fundamental inquiry: Are we alone?