Who lives on the edge of space? That is, who, apart pilots and rare divers in the sky? To this question and was about to answer one of the employees of NASA.

The moon through the upper atmosphere. The picture was taken in December 2003 from the International space station.

If you try to imagine the conditions suitable for life, the stratosphere comes to mind is far not at once: high, dry, cold. This atmospheric layer lies above the plot, forming the weather, i.e. at a height of 10 to 50 km above the Earth's surface. The average temperature of the lower part is -56 C, and the jet stream blows with a speed of 160 km/H. the density of the atmosphere is less than 10% of the index at sea level. Oxygen exists in the form of ozone, which covers everything below it, from ultraviolet radiation of space, but above it (that is, above 32 km) protection no.

A great place to search for living organisms, is not it? Yes, I am a biologist David Smith from the University of Washington (USA), where you can find microbes from almost all domains.

Mr. Smith busy in the Space center. Kennedy "Microorganisms in the stratosphere" (Microorganisms in the Stratosphere, MIST), which aims to census life at a height of several thousand meters above Ground. With the help of high-altitude meteosalon and samples taken by the Observatory on the volcano Bachelor, Oregon), the researchers intend to clarify, where is the line of the biosphere.

Messages that microorganisms can survive at altitudes of up to 77 km, proceed with the 1930-ies, but Mr. Smith does not meet the reliability of old data. Perhaps microbes were listed on the big height by the scientific equipment. "In the articles of those years did not say anything about sterilization", - stressed the expert.

Some researchers have suggested that discovered forms of life were brought from space, but Mr. Smith is confident in their earthly origin. Most of them - bacterial spores, that is extremely resistant organisms with a protective membrane, which is able to transfer and low temperature and dryness, and a high level of radiation. Most likely, them throw dust storms and hurricanes, and then they fly around the world. Down and finding the right conditions, the debate alive.

Information about how and who lives in the stratosphere, will shed light on the ability of the organisms to survive in a terribly difficult conditions on other planets, and first of all on Mars. It will be interesting to see what changes and genetic mutations can experience microbes at high altitudes, especially on the other side of the ozone layer.

Workshop of David Smith on the aforesaid subject:

Based on the materials Astrobiology Magazine.