Martian sub-surface ionising radiation: biosignatures and geology
The surface of Mars, unshielded by thick atmosphere or global magnetic field, is exposed to high levels of cosmic radiation. This ionising radiation field is deleterious to the survival of dormant cells or spores and the persistence of molecular biomarkers in the subsurface, and so its characterisat...
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ftwestminres:oai:westminsterresearch.westminster.ac.uk:qw6z6 2023-05-15T16:37:45+02:00 Martian sub-surface ionising radiation: biosignatures and geology Dartnell, L. Desorgher, L. Ward, J.M. Coates, A.J. 2007 application/pdf https://westminsterresearch.westminster.ac.uk/item/qw6z6/-martian-sub-surface-ionising-radiation-biosignatures-and-geology https://westminsterresearch.westminster.ac.uk/download/7bd214ad664c77a3c410b81c50e5c6530d6ba0b126c12b3d9a8643963cce1edb/1155730/4-Dartnell2007_Biogeosciences.pdf unknown European Geosciences Union https://westminsterresearch.westminster.ac.uk/download/7bd214ad664c77a3c410b81c50e5c6530d6ba0b126c12b3d9a8643963cce1edb/1155730/4-Dartnell2007_Biogeosciences.pdf Dartnell, L., Desorgher, L., Ward, J.M. and Coates, A.J. 2007. Martian sub-surface ionising radiation: biosignatures and geology. Biogeosciences. 4, pp. 545-558. CC BY-NC-SA 2.5 article 2007 ftwestminres 2023-03-26T20:33:38Z The surface of Mars, unshielded by thick atmosphere or global magnetic field, is exposed to high levels of cosmic radiation. This ionising radiation field is deleterious to the survival of dormant cells or spores and the persistence of molecular biomarkers in the subsurface, and so its characterisation is of prime astrobiological interest. Here, we present modelling results of the absorbed radiation dose as a function of depth through the Martian subsurface, suitable for calculation of biomarker persistence. A second major implementation of this dose accumulation rate data is in application of the optically stimulated luminescence technique for dating Martian sediments. We present calculations of the dose-depth profile in the Martian subsurface for various scenarios: variations of surface composition (dry regolith, ice, layered permafrost), solar minimum and maximum conditions, locations of different elevation (Olympus Mons, Hellas basin, datum altitude), and increasing atmospheric thickness over geological history. We also model the changing composition of the subsurface radiation field with depth compared between Martian locations with different shielding material, determine the relative dose contributions from primaries of different energies, and discuss particle deflection by the crustal magnetic fields. Article in Journal/Newspaper Ice permafrost University of Westminster: WestminsterResearch Olympus ENVELOPE(156.767,156.767,-80.217,-80.217) |
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University of Westminster: WestminsterResearch |
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The surface of Mars, unshielded by thick atmosphere or global magnetic field, is exposed to high levels of cosmic radiation. This ionising radiation field is deleterious to the survival of dormant cells or spores and the persistence of molecular biomarkers in the subsurface, and so its characterisation is of prime astrobiological interest. Here, we present modelling results of the absorbed radiation dose as a function of depth through the Martian subsurface, suitable for calculation of biomarker persistence. A second major implementation of this dose accumulation rate data is in application of the optically stimulated luminescence technique for dating Martian sediments. We present calculations of the dose-depth profile in the Martian subsurface for various scenarios: variations of surface composition (dry regolith, ice, layered permafrost), solar minimum and maximum conditions, locations of different elevation (Olympus Mons, Hellas basin, datum altitude), and increasing atmospheric thickness over geological history. We also model the changing composition of the subsurface radiation field with depth compared between Martian locations with different shielding material, determine the relative dose contributions from primaries of different energies, and discuss particle deflection by the crustal magnetic fields. |
format |
Article in Journal/Newspaper |
author |
Dartnell, L. Desorgher, L. Ward, J.M. Coates, A.J. |
spellingShingle |
Dartnell, L. Desorgher, L. Ward, J.M. Coates, A.J. Martian sub-surface ionising radiation: biosignatures and geology |
author_facet |
Dartnell, L. Desorgher, L. Ward, J.M. Coates, A.J. |
author_sort |
Dartnell, L. |
title |
Martian sub-surface ionising radiation: biosignatures and geology |
title_short |
Martian sub-surface ionising radiation: biosignatures and geology |
title_full |
Martian sub-surface ionising radiation: biosignatures and geology |
title_fullStr |
Martian sub-surface ionising radiation: biosignatures and geology |
title_full_unstemmed |
Martian sub-surface ionising radiation: biosignatures and geology |
title_sort |
martian sub-surface ionising radiation: biosignatures and geology |
publisher |
European Geosciences Union |
publishDate |
2007 |
url |
https://westminsterresearch.westminster.ac.uk/item/qw6z6/-martian-sub-surface-ionising-radiation-biosignatures-and-geology https://westminsterresearch.westminster.ac.uk/download/7bd214ad664c77a3c410b81c50e5c6530d6ba0b126c12b3d9a8643963cce1edb/1155730/4-Dartnell2007_Biogeosciences.pdf |
long_lat |
ENVELOPE(156.767,156.767,-80.217,-80.217) |
geographic |
Olympus |
geographic_facet |
Olympus |
genre |
Ice permafrost |
genre_facet |
Ice permafrost |
op_relation |
https://westminsterresearch.westminster.ac.uk/download/7bd214ad664c77a3c410b81c50e5c6530d6ba0b126c12b3d9a8643963cce1edb/1155730/4-Dartnell2007_Biogeosciences.pdf Dartnell, L., Desorgher, L., Ward, J.M. and Coates, A.J. 2007. Martian sub-surface ionising radiation: biosignatures and geology. Biogeosciences. 4, pp. 545-558. |
op_rights |
CC BY-NC-SA 2.5 |
_version_ |
1766028046081458176 |