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Fwd = If Life Exists On Mars, Our Robotic Probes May Have Brought It There

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  • Frits Westra
    Forwarded by: fwestra@hetnet.nl (Frits Westra) URL: http://www.spacedaily.com/news/life-01zg1.html Original Date: 2 Oct 2001 06:07:37 -0000
    Message 1 of 1 , Oct 2, 2001
      Forwarded by: fwestra@... (Frits Westra)
      URL: http://www.spacedaily.com/news/life-01zg1.html
      Original Date: 2 Oct 2001 06:07:37 -0000

      ========================== Forwarded message begins ======================


      If Life Exists On Mars, Our Robotic Probes May Have Brought It There

      by Laura Woodmansee

      Pasadena - Oct 1, 2001

      The results of NASA's 1976 Viking lander missions were largely
      inconclusive. But, what if our spacecraft brought tiny forms of Earth
      life to Mars? Could it have survived there? If so, what does this mean
      for the future exploration of Mars?

      And there is Europa, probably the most likely source of
      extra-terrestrial life in our solar system. NASA has plans to send an
      orbiter and then a lander to search for signs of life in Europa's
      planet-wide ocean. What is being done to protect Europan life?

      How can we seek out life in the solar system without harming it? Can
      robotic probes built on Earth be made clean enough to search for life
      on other planets without contaminating it? If we bring samples of
      alien life back to Earth, how do we prevent them from contaminating
      Earth's biosphere?

      "Planetary protection" is the prevention of "cross contamination."
      That is, preventing life from getting from one planet to another and
      causing harm. It's an important factor in space exploration that the
      public is barely aware of, but one that NASA spends a lot of time
      working on.

      Dr. Karen Buxbaum, a supervisor of the Jet Propulsion Lab's (JPL)
      Planetary Protection Technologies Group says, "There's a certain
      amount of responsibility that we have as an agency that's doing
      exploration to not be sort of reckless in dumping stuff in other parts
      of the solar system."

      NASA divides planetary protection concerns into two categories;
      forward and backward contamination.

      Backward contamination is the type of thing that books and movies like
      H.G. Wells' "War of the Worlds" and Michael Crichton's "The Andromeda
      Strain" have made popular. It is the contamination of Earth life by
      alien spores, microbes or organisms.

      Science fiction has put the fear of contamination by alien life in our
      minds. But, what about the reverse? Could our space probes be
      "infecting" other worlds with Earth life?

      It turns out that NASA is working to protect life on other worlds from
      Earth life, what the space agency calls forward contamination. Buxbaum
      defines it this way; "Forward contamination refers to contamination of
      other solar system bodies with biological material from the Earth."
      But, this concern for alien life remains largely unknown to the
      American public.

      Should we care if we spread Earth life to other planets in our solar
      system, or anywhere else? NASA cares and that's why the agency has
      spent over 30 (1967-2001) years and countless dollars trying to
      prevent cross contamination.

      Protecting life on other planets is important business for NASA. It is
      crucial to the exploration of the solar system. So much so that NASA
      has created an entire Planetary Protection branch. Dr. John Rummel,
      NASA's Planetary Protection Officer, works to protect life on Earth
      and life elsewhere based on NASA's planetary protection policy.

      "The policy is actually based on the desire to preserve
      extraterrestrial environments for the science opportunities that are
      there," says Rummel.

      In other words, if we bring Earth life with us to another planet,
      there is the chance that we may kill or harm indigenous life. Or, we
      may make it harder to determine if life ever existed there. We may
      mistake Earth life for alien life.

      "It's in nobody's best interest to obscure that by contamination with
      Earth organisms," says Rummel. "Nor would you want to discover a
      wonderful new life form and know that you've killed it Essentially we
      can meet ethical considerations by the desire to preserve science."

      Rummel must approve every NASA space probe before launch. "I often
      imagine myself strapped to a booster somewhere," Rummel says in a
      comic voice," 'Now, you won't launch this unless you get my
      signature.'"

      The search for life beyond the Earth has lead to the new science of
      Astrobiology. Through a combination of many physical and life
      sciences, astrobiologists seek out life elsewhere in the solar system
      and the universe. It's important to know where life might be in order
      to understand where it must be protected. Scientists are only now
      starting to understand the so-called "habitable zone," the range of
      environments where life can exist.

      Rummel ties astrobiology to planetary protection saying, "The idea of
      astrobiology [is] to study the origin, evolution, and distribution of
      life in the universe. And its extremely complementary on one level
      with planetary protection, in that by preserving the environments in
      outer space, you give yourself the potential to be able to discover
      more about them."

      On Earth, where there is water, there is life. But life doesn't need
      water to survive. In the past decade, scientists have discovered
      "extremophiles", organisms that live in the limits of the Earth's
      environment. Scientists have found life near hydrothermal vents at the
      bottom of the ocean, deep inside solid rock, and even at the core of
      nuclear reactors.

      "One of the things that's changed in biology," Rummel says, "Is we've
      found life in extreme environments on Earth, that are completely
      different from anything you or I would be comfortable living in.
      Nevertheless, there would be ample opportunity to have life there. I
      don't want to live in a boiling pool in the middle of Yellowstone
      Park, but there are microbes that just love it."

      Astronomers have found all the necessary ingredients for life (water,
      carbon, hydrogen, oxygen and nitrogen) inside clouds of gas and dust
      floating in deep space. At last count, our solar system has one star,
      the Sun, 9 planets with 68 moons, and thousands of comets and
      asteroids. It's quite possible that life arose in at least one of
      these places.

      Detecting life is difficult, and scientists must be careful not to
      confuse Earth life with alien life. This would risk ruining future
      life detection experiments. Karen Buxbaum says, "Confusing the
      scientific results is a threat to the program."

      In the near future, NASA plans to use astrobiology to search for life
      on Mars again. JPL scientist Dr. Roger Kern is planning for such a
      mission. "What we anticipate will happen with the first landers on
      Mars is there will be life detection experiments done in-situ, at the
      site," says Kern. "And those experiments are probably not going to be
      looking for life, per se, but will be looking for molecules associated
      with life. So we want to remove as much [Earth life] as possible."

      Kern continues, "Where as once NASA was only concerned with
      sterilizing spacecraft and making sure that the spacecraft couldn't
      shed a live organism, now we have an interest in seeing to it that it
      doesn't shed a dead organism as well it kind of takes you into a new
      definition of clean."

      Even with super clean spacecraft, some microbes will always get by.
      Dr. Rummel says that the current planetary protection plan includes,
      "An inventory of organic constituents that might be delivered to
      another body. So that if you happen to go back there and find these
      things you know that you brought them."

      In preparing a spacecraft for launch, technicians take samples of any
      microbes, spores, or cells on the spacecraft's surfaces. They work to
      reduce the number of contaminants to as low as possible, cleaning
      several times if needed.

      Part 2: http://www.spacedaily.com/news/life-01zg2.html

      SPACE.WIRE

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