Multiple specimens that closely resemble calcium-encrusted cyanobacteria (blue-green algae) were photographed by NASA’s rover Curiosity in Gale Crater, Mars, several having a blue-green coloration. Comparisons of sequential photos, taken three to five days apart, indicate that putative cyanobacteria are growing, changing shape, multiplying, and secreting spreading pools of what may be calcium carbonate. Specimens that resemble algae/cyanobacteria were first observed during NASA’s Viking Mission and have since been reported in other areas of Mars. Structures resembling microbialites and stromatolites--presumably fashioned by cyanobacteria--have been previously observed in Gale Crater. Cyanobacteria are also primary oxygen producers and the Martian atmosphere is continually replenished with oxygen. Some of the specimens reported here may have been infiltrated by fungi. It has been previously reported, based on sequential photos by the rovers Opportunity and Curiosity, that fungi grow, change shape, increase in size, and multiply. The observations and photos presented in this and other reports strongly support the theory that biologically active cyanobacteria have colonized Mars.
