Viking’s biochemistry experiments have been among the most hotly debated scientific results of all time. The lander famously collected samples from the Red Planet in 1976, in an experiment called “Label Release.” Scientists watched with bated breath as oxygen was released from the sample after it was subjected to a liquid slurry. They were then left scratching their heads as that oxygen production continued after the sample was sterilized via 160 degree C heat. Scientists now really agree that the oxygen production that Viking noticed was an abiotic process. But that also leads to a potential opportunity as some scientists think we can make oxygen farms out of a system similar to that used on Viking itself.
Reactive oxygen species found in the Martian soil most likely reacted with liquid water, causing those reactive species to release their oxygen and turn into a more mundane and less dangerous material. Continual exposure to reactive oxygen species comes with a whole slew of detrimental side effects, such as burns and potentially cancer. And just those kinds of species are all over the surface of both the moon and Mars.
Model of the Viking lander that performed the experiments that inspired the search for the current tool under development.
Credit – NASA / JPL-Caltech / University of Arizona
Therefore, any technique to eliminate those potentially dangerous materials is welcome. In our bodies, antioxidants play the role of reactive agent fighters. Whereas Mars or the Moon doesn’t have such a defense mechanism, humans might build one. It might even be able to act as a sort of “oxygen farm,” allowing the oxygen released by these abiotic reactions to be transferred to breathable air.
First, explorers would have to see where those reactive species are. The best way to do that would be via a detector, and Prof. Christos Georgiou of the University of Patras thinks he has an excellent method to find them – by using a slightly modified version of Viking’s original experiment.
UT video discussing the viability of growing crops on Mars.Using a microfluidic channel to introduce a small amount of liquid to samples collected by explorers themselves would release oxygen in the presence of reactive oxygen species. That oxygen release could act as at least a binary check of whether those species were present or not.
Such a binary check would be useful for more than just whether or not there would be potentially harmful chemicals in the area – it would also help limit the scope of the search for former life on these worlds. Reactive oxygen species would destroy any biological matter they come into contact with, so the chances of finding a fossil or another signature biomarker around large amounts of reactive species would be negligible.
Poster description of how the detection mechanism would work.
Credit – National Technical University of Athens / University of Patras
Understanding those constraints would help define where it would be best to search. It would also point astronauts to a viable potential source of a vital resource for space exploration – oxygen. If scaled up, the same experiment that could be used to detect the presence of reactive oxygen species could be used to harvest the oxygen from those species themselves. According to the researcher’s calculations, a three-acre field could produce enough to supply an astronaut with oxygen continually.
That supply could be continuous because reactive species are constantly being created on these unprotected worlds by UV bombardment from the Sun. If the oxygen farming tool unlocks all the oxygen from the reactive species in a specific area, simply leaving it exposed to direct sunlight would again make it oxidized, allowing the same tool to repeat the process yet again.
Reactive species aren’t only present on planets and moons, though – they could be caused by cosmic radiation on metal or other materials used on spacecraft themselves. Additionally, reactive species are even present on Earth, albeit in smaller quantities. Even in small amounts, though, they still have the potential to do irreparable harm to living, breathing (or non-breathing) biological systems. In either case, such a reactive oxygen species detector could save lives both on other planets, in space, and on our own blue ball.
Artist depiction of a oxygen farming system that could collect enough oxygen to support three astronauts.Credit – National Technical University of Athens / University of Patras
There’s still a long way to go before any device is up and running, though. The European Space Agency is sponsoring a program by the University of Patras and 01 Mechatronics to research further how the system would work on the Moon or Mars. To do so, they are leveraging simulants of Martian soil and hoping to get a chance to test it on some real Moon rocks.
Preliminary testing has gone well so far, and there is undoubtedly a commercial application for a reactive species detector both in space and on Earth. With luck, what might have been viewed as a failed experiment on a different planet could birth a whole sub-branch of the chemical detection industry.
Learn More:
ESA – Moon and Mars superoxides for oxygen farming
Zisimopoulos et al. – Detection of superoxide radical in all biological systems by Thin Layer Chromatography
Atlas – Corrosive Martian and lunar soils could be used to farm oxygen
Lead Image:
Overview of the Martian landscape
Credit – NASA / JPL – Caltech / MSSS
