Hostname: page-component-cd9895bd7-fscjk Total loading time: 0 Render date: 2024-12-23T14:12:28.419Z Has data issue: false hasContentIssue false

Survival of seeds in hypervelocity impacts

Published online by Cambridge University Press:  04 December 2008

Aaron Jerling
Affiliation:
School of Physical Sciences, Ingram Building, University of Kent, Canterbury, Kent CT2 7NH, UK
Mark J. Burchell
Affiliation:
School of Physical Sciences, Ingram Building, University of Kent, Canterbury, Kent CT2 7NH, UK
David Tepfer
Affiliation:
Biologie de al Rhizosphére, Institut National de la Recherche Agronomique, F-78026 Versailles, Francee-mail: [email protected]

Abstract

Panspermia (‘seeds everywhere’) postulates that life naturally migrates through space. Laboratory studies of Panspermia often examine the survival of Earth's species under the conditions thought to occur during transfer through space. Much of this research has centred on bacteria, but here we consider seeds themselves. We simulated the extreme accelerations necessary for their hypothetical ejection from a planetary surface and the impacts associated with their arrival on another planet. Seeds of tobacco, alfalfa and cress were fired into water at speeds in the range 1–3 km s−1, corresponding to impact shock pressures of circa 0.24–2.4 GPa. No seeds remained intact and able to germinate, even at the lowest speeds. Although fragmentation occurred, even at 3 km s−1 the size of some of the fragments was about 25% that of the seeds. Thus, whilst the seeds themselves did not survive extreme shocks, a substantial fraction of their mass did and might successfully deliver complex organic materials after impact. These results are discussed with respect to ancient Panspermia and the potential of contemporary impacts to eject living organisms into space.

Type
Research Article
Copyright
Copyright © 2008 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Armstrong, J.C., Wells, L.E. & Gonzales, G. (2002). Rummaging through Earth's attic for remains of ancient life. Icarus 160, 183196.CrossRefGoogle Scholar
Bowden, S.A., Court, R.W., Milner, D., Baldwin, E.C., Lindgren, P., Crawford, I.A., Parnell, J. & Burchell, M.J. (2008). The thermal alteration by pyrolysis of the organic component of small projectiles of mudrock during capture at hypervelocity. J. Anal. Appl. Pyrol. 82, 312314.CrossRefGoogle Scholar
Burchell, M.J. (2004). Panspermia today. Int. J. Astrobiology 3, 7380.CrossRefGoogle Scholar
Burchell, M.J., Cole, M.J., McDonnell, J.A.M. & Zarnecki, J.C. (1999). Hypervelocity impact studies using the 2 MV Van de Graaff dust accelerator and two stage light gas gun of the University of Kent at Canterbury. Meas. Sci. Technol. 10, 4150.CrossRefGoogle Scholar
Burchell, M.J., Galloway, J.A., Bunch, A.W. & Brandao, P. (2003). Survivability of bacteria ejected from icy surfaces after hypervelocity impact. Orig. Life. Evol. Biosph. 33, 5374.CrossRefGoogle ScholarPubMed
Burchell, M.J., Mann, J.R. & Bunch, A.W. (2004). Survival of bacteria and spores under extreme pressures. Mon. Not. R. Astron. Soc. 352, 12731278.CrossRefGoogle Scholar
Burchell, M.J., Mann, J., Bunch, A.W. & Brandão, P.F.B. (2001). Survivability of bacteria in hypervelocity impact. Icarus 154, 545547.CrossRefGoogle Scholar
Clark, B.C. (2001). Planetary exchange of bioactive material: probability factors and implications. Orig. Life. Evol. Biosph. 31, 185197.CrossRefGoogle Scholar
Clark, B.C. et al. (1999). Survival of life on asteroids, comets and other small bodies. Orig. Life. Evol. Biosph. 29, 521545.CrossRefGoogle ScholarPubMed
Crawford, I.A., Baldwin, E.C., Taylor, E.A., Bailey, J.A. & Tsembelis, K. (2008). On the survivability and detectability of terrestrial meteorites on the moon. Astrobiology 8, 242252.CrossRefGoogle ScholarPubMed
Crick, F.H.C. & Orgel, L.E. (1973). Directed panspermia. Icarus 19, 341346.CrossRefGoogle Scholar
Davies, R.E. (1988). Panspermia: unlikely, unsupported, but just possible. Acta Astronautica 17, 129135.CrossRefGoogle Scholar
Hölzel, N. & Otte, A. (2003). Restoration of a species-rich flood meadow by topsoil removal and diaspore transfer with plant material. Appl. Vegetation Sci. 6, 131140.Google Scholar
Horneck, G., Stöffler, D., Eschweiler, U. & Hornermann, U. (2001a). Bacterial spores survive simulated meteorite impact. Icarus 149, 285–209.CrossRefGoogle Scholar
Horneck, G. et al. (2001b). Protection of bacterial spores in space, a contribution to the discussion on panspermia. Orig. Life. Evol. Biosph. 31, 527547.CrossRefGoogle Scholar
Melosh, H.J. (1988). The rocky road to Panspermia. Nature 332, 687688.CrossRefGoogle ScholarPubMed
Melosh, H.J. (1989). Impact Cratering: A Geological Process. Oxford University Press, Oxford.Google Scholar
Mileikowsky, C. et al. (2000). Natural transfer of viable microbes in space: 1. From Mars to Earth and Earth to Mars. Icarus 145, 391427.CrossRefGoogle Scholar
Milner, D.J., Burchell, M.J., Creighton, J.A. & Parnell, J. (2006). Oceanic hypervelocity impact events: a viable mechanism for successful panspermia? Int. J. Astrobiology 5, 261267.CrossRefGoogle Scholar
Nicholson, W.L., Schuerger, A.C. & Setlow, P. (2005). The solar UV environment and bacterial spore UV resistance: considerations for Earth-to-Mars transport by natural processes and human spaceflight. Mutation Res. 571, 249264.CrossRefGoogle ScholarPubMed
Parsons, P. (1996). Dusting off panspermia. Nature 383, 221222.CrossRefGoogle ScholarPubMed
Pierazzo, E. & Melosh, H.J. (2000). Understanding oblique impacts from experiments, observations and modelling. Ann. Rev. Earth. Planet. Sci. 28, 141167.CrossRefGoogle Scholar
Stöffler, D. et al. (2007). Experimental evidence for the potential impact ejection of viable microorganisms from Mars and Mars-like planets. Icarus 186, 585588.CrossRefGoogle Scholar
Tepfer, D. & Leach, S. (2006). Planet seeds as model vectors for the transfer of life through space. Astrophys. Space. Sci. 306, 6975.CrossRefGoogle Scholar
Wickramasinghe, N.C. et al. (2003). Progress towards the vindication of Panspermia. Astrophys. Space. Sci. 282, 403413.CrossRefGoogle Scholar
Zalar, A., Tepfer, D.A., Hoffmann, S.V., Kollmann, A. & Leach, S. (2007). Directed exospermia: II. VUV–UV spectroscopy of specialized UV screens, including plant flavonoids, suggests using metabolic engineering to improve survival in space. Int. J. Astrobiology 6, 291301.CrossRefGoogle Scholar