| Blue Green | | | | other things. |
| Chroococcidiopsis is a genus of blue-green algae. It | | | | Could it grow on Mars? |
| is very widely distributed on the Earth | | | | Imre Friedmann of NASA's Astrobiology Institute |
| | | | has suggested Chroococcidiopsis as an organism |
| Chroococcidiopsis is a polyextremophile. It is | | | | that could be grown on Mars if the temperature |
| frequently found in several types of extreme | | | | of that planet were raised. Of course there is a |
| environment. It will grow in extremely salty | | | | question of how well we want it to grow. Mr. |
| conditions in marshes, as well as hot and cold | | | | Friedmann is not talking about having it just |
| deserts. | | | | survive, but about it growing well enough to |
| Drying out | | | | prepare the place for other plants. |
| In deserts this organism will often spend most of | | | | Chroococcidiopsis grows in the Antarctic dry |
| is life looking totally dried out. When there is water | | | | valleys which have a similar summer temperature |
| available, it will resume its growth. | | | | to than of the Martian equator. I think the limiting |
| Cold and Dark | | | | factor to its survival would be the question of |
| Chroococcidiopsis is one of the important | | | | whether any film of water forms on the Martian |
| organisms growing in the dry valleys of Antarctica | | | | rocks. Although I am not aware that this has |
| where the hottest air temperature ever recorded | | | | been detected, since there is water underground |
| is about the freezing point of water. In this | | | | on Mars, and the temperature of the soil (Not the |
| environment, it will grow actually underneath | | | | Air) get well above freezing point, some liquid |
| stones where the amount of light is only a | | | | water film under rocks seems possible. |
| thousandth of the Antarctic sunlight. | | | | Atmosphere |
| When the soil and rocks warm up a bit in the | | | | Chroococcidiopsis does not have to have Oxygen. |
| southern summer, tiny amounts of water will | | | | The gas that it does need is Carbon dioxide. The |
| melt, forming a thin layer of moisture which allows | | | | Martian atmosphere actually has more of this gas |
| the algae to photosynthesise and grow. | | | | than the Earth's. A thing that can limit the growth |
| Radiation | | | | of Chroococcidiopsis is lack of Nitrogen. However, |
| Like many organisms that can survive drying out, | | | | this is in the Earth's atmosphere. Under anaerobic |
| Chroococcidiopsis is also moderately resistant to | | | | conditions it will fix atmospheric Nitrogen. It is quite |
| radiation. | | | | likely that on Mars, with its very low level of |
| Spore Forming | | | | Oxygen, Chroococcidiopsis could use the Nitrogen |
| Chroococcidiopsis forms resistant endospores | | | | gas from the atmosphere. |
| which greatly aid its distribution by the wind and | | | | |