Hostname: page-component-78c5997874-j824f Total loading time: 0 Render date: 2024-11-18T07:40:39.115Z Has data issue: false hasContentIssue false
  • English
  • Français

Thermal decomposition rate of MgCO3 as an inorganic astrobiological matrix in meteorites

Published online by Cambridge University Press:  13 April 2016

E. Bisceglia ,
G. Micca Longo  and
S. Longo
E. Bisceglia
Affiliation:
Dipartimento di Chimica, Università degli Studi di Bari, via Orabona 4, I-70126 Bari, Italy
G. Micca Longo
Affiliation:
Dipartimento di Chimica, Università degli Studi di Bari, via Orabona 4, I-70126 Bari, Italy CNR-NANOTEC, Bari section, via Amendola 122/D, I-70126 Bari, Italy
S. Longo*
Affiliation:
Dipartimento di Chimica, Università degli Studi di Bari, via Orabona 4, I-70126 Bari, Italy CNR-NANOTEC, Bari section, via Amendola 122/D, I-70126 Bari, Italy INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze, Italy e-mail: e.bisceglia2@studenti.uniba.itgaia.miccalongo@nanotec.cnr.it
*
savino.longo@nanotec.cnr.it
Get access Rights & Permissions [Opens in a new window]

Abstract

Carbonate minerals, likely of hydrothermal origins and included into orthopyroxenite, have been extensively studied in the ALH84001 meteorite. In this meteorite, nanocrystals comparable with those produced by magnetotactic bacteria have been found into a carbonate matrix. This leads naturally to a discussion of the role of such carbonates in panspermia theories. In this context, the present work sets the basis of a criterion to evaluate whether a carbonate matrix in a meteor entering a planetary atmosphere would be able to reach the surface. As a preliminary step, the composition of carbonate minerals in the ALH84001 meteorite is reviewed; in view of the predominance of Mg in these carbonates, pure magnesite (MgCO3) is proposed as a mineral model. This mineral is much more sensitive to high temperatures reached during an entry process, compared with silicates, due to facile decomposition into MgO and gaseous carbon dioxide (CO2). A most important quantity for further studies is therefore the decomposition rate expressed as CO2 evaporation rate J (molecules/m2 s). An analytical expression for J(T) is given using the Langmuir law, based on CO2 pressure in equilibrium with MgCO3 and MgO at the surface temperature T. Results suggest that carbonate minerals rich in magnesium may offer much better thermal protection to embedded biological matter than silicates and significantly better than limestone, which was considered in previous studies, in view of the heat absorbed by their decomposition even at moderate temperatures. This first study can be extended in the future to account for more complex compositions, including Fe and Ca.

Keywords

CarbonatesLangmuir lawmeteorspanspermia
Type
Research Article
Information
International Journal of Astrobiology , Volume 16 , Issue 2 , April 2017 , pp. 130 - 136
Copyright
Copyright © Cambridge University Press 2016 

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

Atkins, P. & De Paula, J. (2002). Atkins Physical Chemistry, 7th edn. Oxford University Press Inc., New York.Google Scholar
Chase, M.W. Jr. (1998). NIST-JANAF Thermochemical Tables, Fourth Edition. J. Phys. Chem. Ref. Data, Monograph 9, 1–1951.Google Scholar
De Giacomo, A., Dell'Aglio, M., De Pascale, O., Longo, S. & Capitelli, M. (2007). Laser induced breakdown spectroscopy on meteorites. Spectrochim. Acta B: At. Spectrosc. 62(12), 1606–1611.CrossRefGoogle Scholar
Dell'Aglio, M., De Giacomo, A., Gaudiuso, R., De Pascale, O., Senesi, G.S. & Longo, S. (2010). Laser Induced Breakdown Spectroscopy applications to meteorites: chemical analysis and composition profiles. Geochim. Cosmochim. Acta 74(24), 7329–7339.Google Scholar
Dell'Aglio, M., De Giacomo, A., Gaudiuso, R., De Pascale, O. & Longo, S. (2014). Laser Induced Breakdown Spectroscopy of meteorites as a probe of the early solar system. Spectrochim. Acta B: At. Spectrosc. 101, 68–75.Google Scholar
Fentzke, J.T. & Janches, D. (2008) A semi-empirical model of the contribution from sporadic meteoroid sources on the meteor input function in the MLT observed at Arecibo. J. Geophys. Res 113, A03304, doi: 10.1029/2007JA012531.Google Scholar
Foucher, F., Westall, F., Brandstätter, F., Demets, R., Parnell, J., Cockell, C.S., Edwards, H.G.M., Bény, J.M. & Brack, A. (2010). Testing the survival of microfossils in artificial martian sedimentary meteorites during entry into Earth's atmosphere: the STONE 6 experiment. Icarus 207, 616–630.Google Scholar
Friedmann, E.I., Wierzchos, J., Ascaso, C. & Winklhofer, M. (2001). Chains of magnetite crystals in the meteorite ALH84001: evidence of biological origin. Proc. Natl. Acad. Sci. USA 98(5), 2176–2181.Google Scholar
Gibson, E.K. Jr., McKay, D.S., Thomas-Keprta, K.L., Wentworth, S.J., Westall, F., Steele, A., Romanek, C.S., Bell, M.S. & Toporski, J. (2001). Life on Mars: evaluation of the evidence within Martian meteorites ALH84001, Nakhla, and Shergotty. Precamb. Res. 106, 15–34.CrossRefGoogle Scholar
Kopp, R.E. & Humayun, M. (2003). Kinetic model of carbonate dissolution in Martian meteorite ALH84001. Geochim. Cosmochim. Acta 67(17), 3247–3256.Google Scholar
Loeb, L.B. (2004) The Kinetic Theory of Gases. Courier Corporation. New York.Google Scholar
Longo, S. (2012). Simple models for meteor entry in planetary atmospheres, IV Workshop of the Italian Astrobiological Society. ‘From Astrophysics to Astrochemistry towards Astrobiology’, Perugia, September 2012.Google Scholar
McKay, C.P., Friedmann, E.I., Frankel, R.B. & Bazylinski, D.A. (2003). Magnetotactic bacteria on Earth and on Mars. Astrobiology 3(2), 263–270.Google Scholar
McKay, D.S., Gibson, E.K. Jr., Thomas-Keprta, K.L., Vali, H., Romanek, C.S., Clemett, S.J., Chillier, X.D.F., Maechling, C.R. & Zare, R.N. (1996). Search for past life on mars: possible relic biogenic activity in martian meteorite ALH84001. Science 273, 924–930.Google Scholar
McKay, D.S., Thomas-Keprta, K.L., Clemett, S.J., Gibson, E.K. Jr., Spencer, L. & Wentworth, S.J. (2009). Life on Mars: Evidence from Martian Meteorites, Report JSC-CN-19247, NASA Johnson Space Center, Houston.Google Scholar
Öpik, E.J. (2004). Physics of Meteor Flight in the Atmosphere. Courier Corporation. New York.Google Scholar
Schirber, M. (2010). The Continuing Controversy of the Mars Meteorite. Astrobiology Magazine exploring the solar system and beyond, 10/21/10. http://www.astrobio.net/exclusive/3653/the-continuing-controversy-of-the-mars-meteorite-.Google Scholar
Thomas-Keprta, K.L., Gibson, S.J., McKay, D.S., Gibson, E.K. & Wentworth, S.J. (2009). Origins of magnetite nanocrystals in Martian meteorite. Geochim. Cosmochim. Acta 73, 6631–6677.Google Scholar