Exposure of Cyanobacterium Nostoc sp. to the Mars-like Stratosphere Environment

See http://tny.im/pM0 — During the HH-19-2 flight mission of the Chinese Scientific Experimental System, dried Nostoc sp. cells were exposed to the stratosphere environment (32,508 m altitude) for 3 h and 22 min. The atmospheric pressure, temperature, relative humidity, and ionizing and non-ionizing radiation levels at that altitude are similar to those on the surface of Mars. Although analyses revealed decreased photosynthetic activity, a decline in autofluorescence, and damage to the cellular morphology in the flight-exposed sample, the death rate was low (28%). Physiological changes were not obvious after the exposure to the Mars-like vacuum conditions. The ground-exposed samples showed a similar…