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Appropriate protection of Mars

Geological and biological processes have eliminated all but the faintest traces of our earliest ancestors on Earth. To understand the origin of life, we must investigate other planets — but we can find what we seek only if we do not contaminate them with Earth life first.

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Figure 1: A Viking lander, enclosed in a bioshield designed to protect against the re-contamination by microbes after heat treatment, is loaded into an oven at the Kennedy Space Center to undergo full-system sterilization.



  1. Meltzer, M. When Biospheres Collide: A History of NASA's Planetary Protection Programs (NASA SP-4234, 2011).

    Google Scholar 

  2. Fairén, A. G. & Schulze-Makuch, D. Nature Geosci. 6, 510–511 (2013).

    Article  Google Scholar 

  3. National Research Council of the National Academies. Assessment of Planetary Protection Requirements for Mars Sample Return Missions (National Academies Press, 2009).

  4. Ammann, W. et al. Mars Sample Return backward contamination – Strategic advice and requirements (European Science Foundation, 2012).

    Google Scholar 

  5. Kelley, D. S., Baross, J. A. & Delaney, J. R. Annu. Rev. Earth Planet. Sci. 30, 385–491 (2002).

    Article  Google Scholar 

  6. Borgonie, G. et al. Nature 474, 79–82 (2011).

    Article  Google Scholar 

  7. Carter, R. & Mendis, K. M. Clin. Microbiol. Rev. 15, 564–594 (2002).

    Article  Google Scholar 

  8. Kim, W. et al. PLoS ONE 8, e62437 (2013).

    Article  Google Scholar 

  9. Schuerger, A. C., Ulrich, R., Berry, B. J. & Nicholson, W. L. Astrobiology 13, 1–17 (2013).

    Article  Google Scholar 

  10. De Vera, J-P. et al. Astrobiology 10, 215–227 (2010).

    Article  Google Scholar 

  11. Bionetics Corporation. Lessons Learned from the Viking Planetary Quarantine and Contamination Control Experience (NASA NASW-4355, 1990).

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Correspondence to John D. Rummel.

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Conley, C., Rummel, J. Appropriate protection of Mars. Nature Geosci 6, 587–588 (2013).

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