Chroococcidiopsis is one of the most primitive cyanobacteria, blue-green algae, known. It is a photosynthetic, coccoidal bacteria and while there are a diversity of species and cultures within the genus, with a diversity of phenotypes, some members of the genus are known for their ability to survive harsh environmental conditions, including both high and low temperatures, ionizing radiation, and high salinity. Organisms that are capable of living in such harsh conditions are referred to as extremophiles.
The ability of Chroococcidiopsis to resist desiccation in arid environments is due in part to the fact that it colonizes the underside of translucent rocks. The underside of these rocks provides enough condensed moisture for growth while the rock's translucent nature allows just enough light to reach the organism for photosynthesis to occur.
Due to its resistance to harsh environmental conditions, especially low temperature, low moisture, and radiation tolerance, Chroococcidiopsis has been thought of as an organism capable of living on Mars. Scientists have speculated about the possibly of introducing Chroococcidiopsis to the Martian environment to aid in the formation of an aerobic environment. In addition to oxygen production, Chroococcidiopsis could aid in the formation of soil on the Martian surface. On Earth, soil is formed from the decomposition of organic matter. On Mars, because there is no organic matter present, the organic material from the microbes themselves would provide the necessary organic matter. The soil and oxygen produced by these organisms could one day provide the conditions necessary for humans to grow food on Mars, possibly allowing for permanent human civilizations on the planet.
A space mission called EXPOSE-R2 was launched on 24 July 2014 aboard the Russian Progress M-24M, and was attached on 18 August 2014 outside the ISS on the Russian module Zvezda. The experiment includes samples of Chroococcidiopsis that will be exposed to simulated Martian atmosphere, UVC radiation and temperature extremes.
- Cumbers, J. & Rothschild, L.J., 2014. Salt Tolerance and Polyphyly in the Cyanobacterium Chroococcidiopsis (Pleurocapsales). J. Phycol. 50: 472–482
- "Greening of the Red Planet". NASA. Retrieved 2011-03-14.
- Billi, Daniela; Friedmann, Hoffer, Caiola, Ocampo-Friedmann (April 2000). "Ionizing-radiation resistance in the desiccation-tolerant cyanobacterium Chroococcidiopsis". Applied and Environmental Microbiology 66 (4): 1489–1492. doi:10.1128/aem.66.4.1489-1492.2000.
- Gronstal, Aaron L. (31 July 2014). "Exploring Mars in low Earth orbit". NASA's Astrobiology Magazine. Retrieved 2014-08-02.
- Kramer, Miriam (18 August 2014). "Russian Cosmonaut Tosses Satellite for Peru During Spacewalk". Space.com. Retrieved 2014-08-19.
- Baqué, Mickael and de Vera, Jean-Pierre; Rettberg, Petra; Billi, Daniela (20 August 2013). "The BOSS and BIOMEX space experiments on the EXPOSE-R2 mission: Endurance of the desert cyanobacterium Chroococcidiopsis under simulated space vacuum, Martian atmosphere, UVC radiation and temperature extremes.". Acta Astronautica 91: 180–186. doi:10.1016/j.actaastro.2013.05.015. ISSN 0094-5765. Retrieved 14 January 2014.