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Assessment of Planetary Protection Requirements for Mars Sample Return Missions (2009) / Chapter Skim
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5 The Potential for Large-Scale Effects
Pages 45-49

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From page 45...
... Thus, a key question posed to the committee is whether a putative martian organism or organisms, inadvertently released from containment, could produce large-scale negative pathogenic effects in humans or have a destructive impact on Earth's ecological systems or environments.1 TYPES OF LARGE-SCALE EFFECTS The potential effects that are of concern about biohazards can be divided into three broad categories: • Large-scale negative pathogenic effects in humans; • Destructive impacts on Earth's ecological systems or environments; and • Toxic and other effects attributable to microbes, their cellular structures, or extracellular products. These concerns are addressed in the following sections.
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From page 46...
... Ecological Effects New discoveries in environmental microbiology continue to expand understanding of the taxonomic and metabolic diversity of the microbial world, yet much remains unknown.13 It is worth noting, however, that extreme environments on Earth have not yet yielded any examples of life forms that are disruptive to ecosystem functions. The risks of environmental disruption resulting from the inadvertent contamination of Earth with putative martian microbes are still considered to be low.
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From page 47...
... The Shergottites show evidence for significant shock metamorphism; however, the Nakhlites, Chassigny, and ALH 8400119 show little evidence of shock damage as a result of ejection from Mars. 20 Passage through Earth's atmosphere heats only the outer few millimeters of a meteorite, and survival of organics in ALH 84001 and of thermally labile minerals in several other martian meteorites indicates that, indeed, only minor heating occurred during ejection from Mars and subsequent passage through Earth's atmosphere.
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From page 48...
... Thus, it is not appropriate to argue that the existence of martian meteorites on Earth negates the need to treat as potentially hazardous any samples returned from Mars via robotic spacecraft. A prudent planetary protection policy must assume that a potential biological hazard exists from Mars sample return and that every precaution should be taken to ensure the complete isolation of any deliberately returned samples, until it can be determined that no hazard exists.
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From page 49...
... Protocol for Detecting Possible Biohazards in Martian Samples Returned to Earth, NASA/CP-20-02-211842, NASA Ames Research Center, Moffett Field, Calif., 2002.   8  National Research Council, The Quarantine and Certification of Martian Samples, National Academy Press, Wash .
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Key Terms

  • martian meteorites
  • sample return
  • planetary protection
  • martian materials
  • putative martian

  • pathogenic effects
  • martian life
  • returned martian
  • martian samples
  • conservative approach

  • life forms
  • viable organisms
  • negative effects
  • return mission
  • international mars

  • martian organisms
  • effects arising
  • potential biohazards
  • potential risks
  • biological materials

  • protocols remains
  • negative pathogenic
  • potential hazards
  • samples returned
  • extreme environments

  • habitable conditions
  • hazard exists
  • returned samples
  • life form
  • testing protocols


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