In DepthPlanetary Science

Fear of microbial taint curbs Mars explorers

See allHide authors and affiliations

Science  11 Aug 2017:
Vol. 357, Issue 6351, pp. 535-536
DOI: 10.1126/science.357.6351.535

eLetters is an online forum for ongoing peer review. Submission of eLetters are open to all. eLetters are not edited, proofread, or indexed.  Please read our Terms of Service before submitting your own eLetter.

Compose eLetter

Plain text

  • Plain text
    No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.
Author Information
First or given name, e.g. 'Peter'.
Your last, or family, name, e.g. 'MacMoody'.
Your email address, e.g. higgs-boson@gmail.com
Your role and/or occupation, e.g. 'Orthopedic Surgeon'.
Your organization or institution (if applicable), e.g. 'Royal Free Hospital'.
Statement of Competing Interests
Publication Date - String
CAPTCHA

This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.

Image CAPTCHA
Enter the characters shown in the image.

Vertical Tabs

  • RE: Relaxing planetary protection could be fatal to future life-seeking missions

    Relaxing planetary protection could be fatal to future life-seeking missions

    The 11 August article, "Fear of microbial taint curbs Mars explorers" (Paul Voosen), comments on NASA's consideration of reducing planetary protection standards for missions to Mars, allowing restrictions placed on the rover Curiosity's freedom to roam into "special regions" of the planet to be relaxed. Such a decision is short-sighted and counter-productive for at least two reasons. First, as reported in the article, Alberto Fairén, a planetary scientist at Cornell University, supports the relaxation regardless of its potential contamination of Mars with Earth organisms. He cites that even if some contaminating organisms do survive, "future missions could distinguish between earthly and martian microbes by sequencing their genomes." That may hold true if you had the alien organism's DNA to sequence. However, much of the ongoing search for potential extraterrestrial life is directed at seeking the signs of life, not the organism itself. For example, NASA's two Viking missions in the late 1970s sought chemical signatures associated with biological activity, such as gasses produced by metabolism, not the discrete organisms themselves. Contamination with Earth organisms may produce similar signatures, confounding future searches. Second, Jim Kasting, a geoscientist at Pennsylvania State University, said that martian soil has proved to...

    Show More
    Competing Interests: None declared.