Forward contamination
Forward contamination is the process when earthly life forms reach other celestial bodies and contaminate them. The counterpart is called reverse contamination designated (reverse / back-contamination).
The Outer Space Treaty of 1967 mentioned in Article IX, the planetary contamination and formulated corresponding demands on the space operated Parties.
To prevent forward contamination, space programs put great effort into sterilization . The umbrella term for this is Planetary Protection .
history
With the US American probe Surveyor 3 , terrestrial microbes reached the moon in 1967 and possibly returned viable through a rescue operation as part of the Apollo 12 mission. They were α- hemolytic streptococci mitis , which occur regularly in the pharynx and are known to be vacuum-dry and very robust. However, the microbes would have had to withstand the hard cosmic radiation and temperature cycles between −160 and +70 ° C for 31 months. They were discovered in just one of many samples from inside the Surveyor camera under conditions that were inadequate even with the then state of clean room technology . People wore gloves, for example, but only short-sleeved shirts, which also did not reach below the front edge of the laminar flow box . Self-contamination was therefore quite possible. The fact that the microbes stayed on the moon is indicated by the fact that they only began to multiply normally in the nutrient medium after a few days. An argument against contamination is that no other species were found. In addition, the camera could easily be contaminated before take-off, because the precautionary measures for lunar missions had been relaxed because, with the knowledge gained up to that point, it was clear that contamination would remain locally limited under lunar conditions. Conversely, according to this finding, the hygiene standards for missions to less hostile celestial bodies were significantly raised.
Web links
- Christine Moissl-Eichinger: Biocontamination in the Space University of Regensburg
- Planetary Protection @ astrobiology.com
- Earth microbes on the moon science.nasa.gov
Individual evidence
- ^ Iain Gilmour, et al .: An introduction to astrobiology. Cambridge Univ. Press, Cambridge 2004, ISBN 0-521-83736-7 , chapter: 3.6 Planetary protection, pp. 119-122
- ↑ Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies - Article IX ( Memento of May 16, 2012 in the Internet Archive ) oosa.unvienna.org, accessed on May 11 2012
- ^ A b F. I. Mitchell, WL Ellis: Surveyor 3: Bacterium Isolated From Lunar-Retrieved Television Camera . In: Analysis of Surveyor 3 material and photographs returned by Apollo 12 . NASA Case File Copy N72.26731-72, 1972, pp. 239-248 (pdf, 24 MB).
- ^ A b Leonard David: Moon Microbe Mystery Finally Solved. Space.com, May 2, 2011, accessed March 13, 2016 .