International Journal of Astrobiology

An analysis of potential photosynthetic life on Mars

John J. Sakon a1a2 and Robert L. Burnap a2a3
a1 The College of William and Mary, Department of Physics, Williamsburg, VA 23185, USA
a2 Department of Physics, NC State University, Raleigh, NC 27607, USA e-mail:
a3 Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK 74078, USA

Article author query
sakon jj   [PubMed][Google Scholar] 
burnap rl   [PubMed][Google Scholar] 


This project researched the possibility of photosynthetic life on Mars. Cyanobacteria were used as potential analogs and were subjected to various Martian-simulated conditions. Synechocystis sp. PCC 6803 was exposed to low pressure, ultraviolet radiation and Martian-simulated atmospheric composition, and proved resistant to the combination of these stresses. However, this organism could neither grow within Martian Regolith Simulant, owing to the lack of soluble nitrogen, nor could it grow in cold temperatures. As a result, later research focused on psychrotolerant cyanobacteria capable of utilizing atmospheric nitrogen. These Antarctic nitrogen-fixing strains were able to grow in Martian Regolith Simulant at temperatures as low as 4 °C. In addition, they proved resistant to salinity, ultraviolet radiation and freeze/thaw conditions. These results suggest that Antarctic nitrogen-fixing cyanobacteria are good analogs for potential Martian life and should be considered in future exploratory missions for life on the red planet.

(Received September 17 2005)
(Accepted August 8 2006)

Key Words: astrobiology; cyanobacteria; extraterrestrial life; Mars; nitrogen fixation; photosynthesis.