Evaluating the Biological Potential in Samples Returned from Planetary Satellites and Small Solar System Bodies Framework for Decision Making (1998) / Chapter Skim
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6 Cosmic Dust
6 Cosmic Dust
Pages 64-68
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From page 64... ...
This factor depends on particle velocity, which decreases with increasing distance from the Sun. How the Poynting-Robertson drag and the disruptive collisional effects influence average IDP lifetimes is difficult to evaluate, but it is likely that in combination these effects act to shorten IDP residence times in the solar system.
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From page 65... ...
Some of the cometary organic compounds such as HCN, aldehydes, and ammonia are involved in the abiotic synthesis of more complex molecules, including amino acids and some of the bases present in DNA and RNA (see, e.g., Miller and Orgel, 1974~. Thus, it is not unreasonable to expect that compounds important in biochemistry may also be present in comets, although this conclusion likely is dependent on whether at some time during a comet's history liquid water was present either on its surface or in its interior.
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From page 66... ...
These results suggest that although cosmic dust has been constantly accreted by Earth during modern times, organic compounds associated with this extraterrestrial debris do not apparently accumulate to measurable concentrations. POTENTIAL FOR A LIVING ENTITY TO BE IN OR ON RETURNED SAMPLES OF COSMIC DUST Because interplanetary dust particles are derived from a variety of sources, including interstellar grains and debris from comets, asteroids, and possibly planetary satellites, IDPs cannot be viewed as a distinct target body.
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From page 67... ...
However, the effect of short-pulse heating on organisms and organic compounds is not well understood. Recent experiments involving the exposure of amino acids to temperatures as high as 1,000 °C for a few seconds have found, surprisingly, that some amino acids survive exposure to high-temperature pulsed heating (D.P.
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From page 68... ...
1991. An interplanetary dust particle linked directly to type CM meteorites and an asteroid origin.
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