Experimental Astrobiology

Life is out there, and we must find it,” has been the approach taken by astrobiology since the birth of NASA’s Exobiology Program in 1960. But what if we said, “Life, as we know it, is here. We can create it out there”?

The human curiosity for space exploration has been overwhelmingly consumed by our red neighbour Mars, from NASA’s Viking lander in the 70s to the sci-fi genre’s thrilling illustrations making their way onto its cratered surface. It was the Viking lander that unknowingly found oxidising salts in Martian soil, which were only identified in 2008 to be perchlorates, possibly an important source of oxygen on Mars. Subsequent missions, including the Curiosity and Perseverance rovers, found evidence of ancient water, organic molecules, and seasonal methane variations, supporting the possibility of past or present microbial life. 

This decades-long endeavour marks just one aspect of a relentless search to find company in the vastness of the universe. Digging into Martian regolith and studying microbes in Earth’s most severe climates, such as Dale Andersen’s investigations into Antarctic dry valleys, are some of the many attempts that astrobiology has made to investigate the possibility of life beyond Earth.  

The Curiosity rover’s Sample Analysis at Mars (SAM) instrument found an atmosphere brimming with carbon dioxide and astronomical levels of radiation and soil toxicity. This made it clear that despite showing evidence of life-sustaining elements such as carbon, nitrogen, and oxygen, Mars is a hostile environment. Consequently, researchers have turned toward bioengineering habitability on Mars, and experimental astrobiology took main stage. 

“Applied astrobiology,” as named by Robin Wordsworth, a Harvard researcher, began in the 1990s with attempts to harbour life in space. Companies and institutes that had been dedicated to pushing out into space now broadened their lens to consider synthesising biological systems for the creation of liveability. With this, we went beyond the idea of enhancing the environment to support the settlement of life and began trying to enable it to create those life-supporting materials itself.    

Dr. Wordsworth and British astrobiologist Charles Cockell have been developing laboratory planetary simulators, taking the popular experimental astrobiology approach of mimicking Earth’s life-sustaining biosphere. This very approach, as co-opted by environmental research facilities like BIOS-3, forms the foundation of the creation of a self-enlarging environment made up of methodically chosen materials and microbes. Wordsworth’s 2019 research on cyanobacteria and algae growing in Mars-like conditions indicated that the possibilities of synthesising liveable environments in the lab are endless, feasible, and thoroughly exciting.  

There is no doubt that the field of synthetic biology is rife with technologies that offer acceleration to experimental astrobiology. Additionally, with the climate crisis posing a threat to humans’ quality of life on Earth, it appears that there is no time more opportune than now to explore habitability on our not-so-friendly neighbour. But with these far-reaching ideas come several concerns. Importantly, is it within our right to do so? 

Currently, all regions of Mars that seem to be peculiarly habitable are sectioned off as “special regions” by the Committee on Space Research (COSPAR). Contamination has always been seen as a failure and a harm, so these regions are barred from being the destination of any missions for the purpose of planetary protection. The regions on Mars identified by the Mars Reconnaissance Orbiter since 2006 that are most likely to sustain life are the very regions that we are unable to explore. 

It is undeniable that our exploration risks overwriting and damaging the Martian ecosystem with the materials and microbes that we wish to introduce into its atmosphere.  

But also, the red planet is perhaps a red herring. This conversation may not concern Mars as much as it may seem: it is simply a representative of an extreme environment devoid of resources, a world that we are able to imagine on our own planet amid ecological and political crises. Mars may not be a destination at all.  

Cockell argues that it is rather unlikely that astrobiological experiments will lead to self-sufficient habitats and colonies on Mars in the near-term. However, Christopher McKay’s research with NASA Ames on organisms that can survive in harsh environments indicates that it is entirely possible and desirable to direct these experiments towards understanding life and its survival in the most unsurvivable of environments. 

Many questions in this field lack answers, and the ethical implications of this pursuit are heavily contested. But the current potential of synthetic biology and rocketry points at a horizon filled with explications of the spheres explored by astrobiology. Importantly, it lights a path toward improving the habitability of Earth.