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Maximum number of habitable planets at the time of Earth’s origin: new hints for panspermia and the mediocrity principle

Published online by Cambridge University Press:  23 March 2007

Siegfried Franck
Affiliation:
Potsdam Institute for Climate Impact Research (PIK), P.O. Box 601203, 14412 Potsdam, Germany e-mail: [email protected]
Werner von Bloh
Affiliation:
Potsdam Institute for Climate Impact Research (PIK), P.O. Box 601203, 14412 Potsdam, Germany e-mail: [email protected]
Christine Bounama
Affiliation:
Potsdam Institute for Climate Impact Research (PIK), P.O. Box 601203, 14412 Potsdam, Germany e-mail: [email protected]

Abstract

In this paper we estimate the number of habitable planets in our Galaxy over cosmological time scales. This number can be derived from the planet formation rate (PFR) of Earth-like planets and the convolution of this value with the probability of being habitable. The PFR is calculated from the star formation rate (SFR) with the help of a so-called Goldilocks problem. The probability that an Earth-like planet is in the habitable zone (HZ) is estimated with the help of our Earth system model. In order to calculate the HZ an integrated system approach is used, taking into account a variety of climatological, biogeochemical, and geodynamical processes. Habitability is linked to the photosynthetic activity on the planetary surface. We find that habitability strongly depends on the age of the stellar system and the characteristics of a virtual Earth-like planet. There was a maximum number of habitable planets around the time of the Earth’s origin and interstellar panspermia was most probable at that time. Furthermore, we discuss our results in the framework of the so-called principle of mediocrity.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2007

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References

Arrhenius, S. (1908). Das Werden der Welten. Academic Publishing House, Leipzig, 208 p.Google Scholar
Baker, J., Bizzarro, M., Wittig, N., Connelly, J. & Haack, H. (2005). Early planetesimal melting from an age of 4.5662 Gyr for differentiated meteorites. Nature 436, 11271131.Google Scholar
Brasier, M.D., Green, O.R., Jephcoat, A.P., Kleppe, A.K., Van Kranendonk, M.J., Lindsay, J.F., Steele, A. & Grassineau, N.V. (2002). Questioning the evidence for Earth’s oldest fossils. Nature 416, 7681.Google Scholar
Caldeira, K. & Kasting, J.F. (1992). The life span of the biosphere revisited. Nature 360, 721723.Google Scholar
Chaboyer, B., Demarque, P., Kernan, P.J. & Krauss, L.M. (1996). A lower limit on the age of the universe. Science 271, 957961.Google Scholar
Cowan, J.J., Pfeiffer, B., Kratz, K.L., Thielemann, F.K., Sneden, C., Burles, S., Tytler, D. & Beers, T.C. (1999). R-process abundances and chronometers in metal-poor stars. Astrophys. J. 521, 194205.Google Scholar
Darling, D.J. (2001). Life Everywhere: the Maverick Science of Astrobiology, pp. 206. Basic Books, New York.Google Scholar
Dauphas, N. (2005). The U/Th production ratio and the age of the Milky Way from meteorites and Galactic halo stars. Nature 435, 12031205.CrossRefGoogle Scholar
Des Marais, D.J., Harwitt, M.O., Jucks, K.W., Kasting, J.F., Lin, D.N.C., Lunine, J.I., Schneider, J., Seager, S., Traub, W.A. & Woolf, N.J. (2003). Remote sensing of planetary properties and biosignatures on extrasolar terrestrial planets. Astrobiology 2, 153181.Google Scholar
Franck, S., Block, A., von Bloh, W., Bounama, C., Garrido, I. & Schellnhuber, H.-J. (2001). Planetary habitability: is Earth commonplace in the Milky Way? Naturwissenschaften 88, 416426.CrossRefGoogle ScholarPubMed
Franck, S., Block, A., von Bloh, W., Bounama, C., Schellnhuber, H.-J. & Svirezhev, Y. (2000a). Reduction of biosphere life span as a consequence of geodynamics. Tellus 52B, 94107.Google Scholar
Franck, S., Cuntz, M., von Bloh, W. & Bounama, C. (2003). The habitable zone of Earth-mass planets around 47 UMa: results for land and water worlds. Int. J. Astrobiol. 2(1), 3539.Google Scholar
Franck, S., Kossacki, K. & Bounama, C. (1999). Modelling the global carbon cycle for the past and future evolution of the earth system. Chem. Geol. 159, 305317.Google Scholar
Franck, S., von Bloh, W., Bounama, C., Steffen, M., Schönberner, D. & Schellnhuber, H.-J. (2000b). Determination of habitable zones in extrasolar planetary systems: where are Gaia’s sisters? J. Geophys. Res. 105(E1), 16511658.CrossRefGoogle Scholar
Hoyle, F. & Wickramasinghe, N.C. (2000). Astronomical Origins of Life: Steps towards Panspermia. Kluwer, Dordrecht.Google Scholar
Kasting, J.F. (1984). Comments on the BLAG model: the carbonate–silicate geochemical cycle and its effect on atmospheric carbon dioxide over the past 100 million years. Am. J. Sci. 284, 11751182.CrossRefGoogle ScholarPubMed
Kasting, J.F., Whitmire, D.P. & Reynolds, R.T. (1993). Habitable zones around main sequence stars. Icarus 101, 108128.Google Scholar
Larcher, W. (1995). Physiological Plant Ecology: Ecophysiology of Functional Groups. Springer, New York.Google Scholar
Lineweaver, C.H. (2001). An estimate of the age distribution of terrestrial planets in the universe: quantifying metallicity as a selection effect. Icarus 151, 307313.Google Scholar
Lineweaver, C.H. & Grether, D. (2003). What fraction of Sun-like stars have planets? Astrophys. J. 598, 13501360.Google Scholar
Marcy, G.W., Butler, R.P., Fischer, D., Vogt, S., Wright, J.T., Tinney, C.G. & Jones, H.R.A. (2005). Observed properties of exoplanets: masses, orbits, and metallicities. Progr. Theor. Phys. Suppl. 158, 2442.Google Scholar
Melosh, H.J. (2001). Exchange of meteoritic material between stellar systems. In Proc. 32nd Conf. on Lunar and Planetary Science, Lunar and Planetary Institute, Houston, TX, Abstract 2022.Google Scholar
Mileikowsky, C., Cucinotta, F.A., Wilson, J.W., Gladman, B., Horneck, G., Lindegren, L., Melosh, J., Rickman, H., Valtonen, M. & Zheng, J.Q. (2000). Natural transfer of viable microbes in space: 1. from Mars to Earth and Earth to Mars. Icarus 145, 391427.Google Scholar
Mojzsis, S.J., Arrhenius, G., McKeegan, K.D., Harrison, T.M., Nutman, A.P. & Friend, C.R.L. (1996). Evidence for life on Earth 3800 million years ago. Nature 384, 5559.CrossRefGoogle Scholar
Nagamine, K., Fukugita, M., Cen, R. & Ostriker, J.P. (2001). Star formation history and stellar metallicity distribution in a Λ cold dark matter universe. Astrophys. J. 558, 497504.Google Scholar
O’Brien, D.P., Morbidelli, A. & Levison, H.F. (2006). Terrestrial planet formation with strong dynamical friction. Icarus 184, 3958.CrossRefGoogle Scholar
Parson, P. (1996). Dusting off panspermia. Nature 383, 221222.Google Scholar
Pearcy, R.W. & Ehleringer, J. (1984). Comparative ecophysiology of C3 and C4 plants. Plant Cell Environ. 7, 113.CrossRefGoogle Scholar
Santos, N.C., Benz, W. & Mayor, M. (2005). Extrasolar planets: constraints for planet formation models. Science 310, 251255.Google Scholar
Schidlowski, M. (1990). Life on early Earth: bridgehead from cosmos or autochthonous phenomenon? In From Mantle to Meteorites, eds Gopalani, K., Gaur, V.R., Somayajulu, B.L.K. & MacDougall, J.D., pp. 189199. Indian Academy of Sciences, Bangalore.Google Scholar
Volk, T. (1987). Feedbacks between weathering and atmospheric CO2 over the last 100 million years. Am. J. Sci. 287, 763779.Google Scholar
von Bloh, W., Bounama, C. & Franck, S. (2006). Dynamic habitability for Earth-like planets in 86 extrasolar planetary systems. Planet. Space Sci. doi: 10.1016/j.pss.2006.06.022.Google Scholar
von Bloh, W., Franck, S., Bounama, C. & Schellnhuber, H.-J. (2003). Maximum number of habitable planets at the time of Earth’s origin: new hints for panspermia? Origins Life Evol. Biosph. 33, 219231.Google Scholar
Vreeland, R.N., Rosenzweig, W.D. & Powers, D.W. (2000). Isolation of a 250 million-year-old halotolerant bacterium from a primary salt crystal. Nature 407, 897900.CrossRefGoogle ScholarPubMed
Wallis, M.K. & Wickramasinghe, N.C. (2004). Interstellar transfer of planetary microbiota. Mon. Not. R. Astron. Soc. 348, 5261.Google Scholar
Weber, P. & Greenberg, J.M. (1985). Can spores survive in interstellar space? Nature 316, 403407.CrossRefGoogle Scholar
Workman, R.K. & Hart, S.R. (2005). Major and trace element composition of the depleted MORB mantle (DMM). Earth Planet. Sci. Lett. 231, 5372.CrossRefGoogle Scholar
Yin, Q., Jacobsen, S.B., Yamashita, K., Blichert-Toft, J., Télouk, P. & Albarède, F. (2002). A short timescale for terrestrial planet formation from Hf–W chronometry of meteorites. Nature 418, 949952.Google Scholar
Zhang, Y. (1998). The young age of Earth. Geochim. Cosmochim. Acta 62, 31853189.CrossRefGoogle Scholar