Astro microbiology

Astro microbiology, or exo microbiology, is the study of

The search for extraterrestrial microbial life have focused mostly on Mars due to its promising environment and close proximity; however, other astrobiological sites include the moons Europa, Titan and Enceladus. All of these sites currently have or have had a recent history of possessing liquid water, which scientists hypothesize as the most consequential precursor for biological life. Europa and Enceladus appear to have large amounts of liquid water hidden beneath the layers of ice that covers their surfaces. Titan, on the other hand, is only planetary body besides Earth with liquid hydrocarbons on its surface. Mars is the main area of interest for the search for life primarily because of convincing evidence that suggests surface liquid water activity in recent history. Furthermore, Mars has an atmosphere containing abundant amounts of carbon and nitrogen, both essential elements needed for life.^[2]

Discoveries

In 1975, NASA's

In operation since 2012, NASA's Curiosity rover has found evidence of historical conditions on Mars being suitable for life, such as organic matter being preserved in rocks and evidence of past groundwater, though no lifeforms have been found.^[5]

In 2014, Vladimir Solovyov of Russia's TASS news agency claimed that cosmonauts found plankton on the International Space Station. NASA officials found no evidence for the claims, though they predicted that some extremophile microorganisms could survive in space.^[6]

Future missions

Experimentation

Earth

Many studies on Earth have been conducted to collect data on the response of terrestrial microbes to various simulated environmental conditions of outer space. The responses of microbes, such as viruses, bacterial cells, bacterial and fungal spores, and lichens, to isolated factors of outer space (microgravity, galactic cosmic radiation, solar UV radiation, and space vacuum) were determined in space and laboratory simulation experiments. In general, microorganisms tended to thrive in the simulated space flight environment – subjects showed symptoms of enhanced growth^[8] and an uncharacteristic ability to proliferate despite the presence of normally suppressive levels of antibiotics. In fact, in one study, trace (background levels) of antibiotic exposure resulted in acquisition of antibiotic resistance under simulated microgravity.^[9] The mechanisms responsible for explaining these enhanced responses have yet to be discovered.^[10]

Space

The ability of microorganisms to survive in an outer space environment was investigated to approximate upper boundaries of the biosphere and to determine the accuracy of the interplanetary transport theory for microorganisms. Among the investigated variables, solar UV radiation had the most harmful effect on microbial samples. Among all the samples, only lichens (

Modern technology has already allowed us to use microbes to assist us in extracting materials on Earth, including over 25% of the our current copper supply. Similarly, microbes could help serve a similar purpose on other planets to mine resources, extract useful materials, or create self-sustaining reactors. The most promising of these candidates known to date is cyanobacteria. Billions of years ago, cyanobacteria originally helped us create a habitable Earth by pumping oxygen into the atmosphere, and manage to exist in the darkest corners of the Earth. Cyanobacteria, along with some other rock-eating microbes, seem to be able to withstand the harsh conditions of the vacuum of space without much effort. On Mars, however, cyanobacteria will not even have to endure such harsh conditions.^[11]

Scientists are currently working on the possibility of installing bioreactors or similar facilities on Mars, which would run entirely on cyanobacteria and provide material for the creation of fuel cells, soil crust formation, regolith amelioration, extraction of useful metals/elements, nutrient release into the soil, and dust removal; a variety of other potentially useful functions are also in the works.^[11]

References