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Life-bearing primordial planets in the solar vicinity |
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| Authors: | N Chandra Wickramasinghe Jamie Wallis Daryl H Wallis Rudolph E Schild Carl H Gibson |
| Institution: | 1. Buckingham Centre for Astrobiology, The University of Buckingham, Buckingham, MK18 1EG, UK 2. School of Mathematics, Cardiff University, Cardiff, UK 3. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA, 02138, USA 4. University of California San Diego, La Jolla, CA, 92093-0411, USA |
| Abstract: | The space density of life-bearing primordial planets in the solar vicinity may amount to ～8.1×104?pc?3 giving total of ～1014 throughout the entire galactic disk. Initially dominated by H2 these planets are stripped of their hydrogen mantles when the ambient radiation temperature exceeds 3?K as they fall from the galactic halo to the mid-plane of the galaxy. The zodiacal cloud in our solar system encounters a primordial planet once every 26 My (on our estimate) thus intercepting an average mass of 103 tonnes of interplanetary dust on each occasion. If the dust included microbial material that originated on Earth and was scattered via impacts or cometary sublimation into the zodiacal cloud, this process offers a way by which evolved genes from Earth life could become dispersed through the galaxy. |
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