Abstract
Terrestrial exoplanets likely form initial atmospheres through outgassing during and after accretion, although there is currently no first-principles understanding of how to connect a planet’s bulk composition to its early atmospheric properties. Important insights into this connection can be gained by assaying meteorites, which are representative samples of planetary building blocks. We perform laboratory outgassing experiments that use a mass spectrometer to measure the abundances of volatiles released when meteorite samples are heated to 1,200 °C. We find that outgassing from three carbonaceous chondrite samples consistently produce H2O-rich (average of ~66%) atmospheres but with substantial amounts of CO (~18%) and CO2 (~15%) as well as smaller quantities of H2 and H2S (up to 1%). These results provide experimental constraints on the initial chemical composition in theoretical models of terrestrial planet atmospheres, and supply abundances for principal gas species as a function of temperature.
This is a preview of subscription content, access via your institution
Access options
Access Nature and 54 other Nature Portfolio journals
Get Nature+, our best-value online-access subscription
$29.99 / 30 days
cancel any time
Subscribe to this journal
Receive 12 digital issues and online access to articles
$119.00 per year
only $9.92 per issue
Rent or buy this article
Prices vary by article type
from$1.95
to$39.95
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
Data availability
Source data are provided with this paper. The data that support the findings of this study and corresponding plots in the paper are available from https://github.com/maggieapril3/CMChondritesOutgassingData or from the corresponding author upon request. Figures 1–4, Extended Data Figs. 1–5 and Supplementary Figs. 2–4 have associated raw data that are available from https://github.com/maggieapril3/CMChondritesOutgassingData or from the corresponding author. The thermochemical equilibrium models used in Figs. 3 and 4 and Extended Data Fig. 5 are available from L.S. (lkschaef@stanford.edu) upon request.
Code availability
The code used to calibrate and analyse the data used in this study is also available from https://github.com/maggieapril3/CMChondritesOutgassingData.
References
Petigura, E. A., Marcy, G. W. & Howard, A. W. A plateau in the planet population below twice the size of Earth. Astrophys. J. 770, 69 (2013).
Petigura, E. A., Howard, A. W. & Marcy, G. W. Prevalence of Earth-size planets orbiting Sun-like stars. Proc. Natl Acad. Sci. USA 110, 19273–19278 (2013).
Dressing, C. D. & Charbonneau, D. The occurrence of potentially habitable planets orbiting M dwarfs estimated from the full Kepler dataset and an empirical measurement of the detection sensitivity. Astrophys. J. 807, 45 (2015).
Sharp, Z. D. Nebular ingassing as a source of volatiles to the terrestrial planets. Chem. Geol. 448, 137–150 (2017).
Schlichting, H. E. & Mukhopadhyay, S. Atmosphere Impact Losses. Space Sci. Rev. 214, 34 (2018).
Wu, J. et al. Origin of Earth’s water: chondritic inheritance plus nebular ingassing and storage of hydrogen in the core. J. Geophys. Res. Planets 123, 2691–2712 (2018).
Lammer, H. et al. Origin and evolution of the atmospheres of early Venus, Earth and Mars. Astron. Astrophys. Rev. 26, 2 (2018).
Elkins-Tanton, L. T. & Seager, S. Ranges of atmospheric mass and composition of super-Earth exoplanets. Astrophys. J. 685, 1237–1246 (2008).
Ahrens, T. J., O’Keefe, J. D. & Lange, M. A. in Origin and Evolution of Planetary and Satellite Atmospheres 328–385 (Univ. of Arizona Press, 1989).
Lodders, K. & Fegley, B. Jr. The Planetary Scientist’s Companion (Oxford Univ. Press, 1998).
Wasson, J. T. & Kallemeyn, G. W. Compositions of chondrites. Philos. Trans. R. Soc. A 325, 535–544 (1988).
Zahnle, K. J., Kasting, J. F. & Pollack, J. B. Evoluation of a steam atmosphere during Earth’s accretion. Icarus 74, 62–97 (1988).
Gaillard, F. & Scaillet, B. A theoretical framework for volcanic degassing chemistry in a comparative planetology perspective and implications for planetary atmospheres. Earth Planet. Sci. Lett. 403, 307–316 (2014).
Schaefer, L. & Fegley, B. Jr. Chemistry of atmospheres formed during accretion of the Earth and other terrestrial planets. Icarus 208, 438–448 (2010).
Herbort, O., Woitke, P., Helling, C. & Zerkle, A. The atmospheres of rocky exoplanets. I. Outgassing of common rock and the stability of liquid water. Astron. Astrophys. 636, A71 (2020).
Court, R. W. & Sephton, M. A. Meteorite ablation products and their contribution to the atmospheres of terrestrial planets: an experimental study using pyrolysis-FTIR. Geochim. Cosmochim. Acta 73, 3512–3521 (2009).
Gooding, J. L. & Muenow, D. W. Experimental vaporization of the Holbrook chondrite. Meteoritics 12, 401–408 (1977).
Lange, M. A. & Ahrens, T. J. The evolution of an impact-generated atmosphere. Icarus 51, 96–120 (1982).
Burgess, R., Wright, I. P. & Pillinger, C. T. Determination of sulphur-bearing components in C1 and C2 carbonaceous chondrites by stepped combustion. Meteoritics 26, 55–64 (1991).
Springmann, A. et al. Thermal alteration of labile elements in carbonaceous chondrites. Icarus 324, 104–119 (2019).
Tyburczy, J. A., Frisch, B. & Ahrens, T. J. Shock-induced volatile loss from a carbonaceous chondrite: implications for planetary accretion. Earth Planet. Sci. Lett. 80, 201–207 (1986).
Ikramuddin, M., Binz, C. M. & Lipschutz, M. E. Thermal metamorphism of primitive meteorites. III. Ten trace elements in Krymka l3 chondrite heated at 400–1000°C. Geochim. Cosmochim. Acta 41, 393–401 (1977).
Krinov, E. L. Fall of Murchison stone meteorite shower, Australia. Meteoritics 5, 85–109 (1970).
Ruzicka, A., Grossman, J., Bouvier, A., Herd, C. D. K. & Agee, C. B. The meteoritical bulletin, no. 102. Meteorit. Planet. Sci. 50, 1662 (2015).
Gattacceca, J., McCubbin, F. M., Bouvier, A. & Grossman, J. N. The meteoritical bulletin, no. 108. Meteorit. Planet. Sci. 55, 1146–1150 (2020).
Nittler, L. R. et al. Bulk element compositions of meteorites: a guide for interpreting remote-sensing geochemical measurements of planets and asteroids. Antarct. Meteor. Res. 17, 231–251 (2004).
Alexander, C. M. O’D. et al. The provenances of asteroids, and their contributions to the volatile inventories of the terrestrial planets. Science 337, 721–723 (2012).
O’Brien, W. J. & Nielsen, J. P. Decomposition of gypsum investment in the presence of carbon. J. Dent. Res. 38, 541–547 (1959).
Zhao, S.-P., Jiang, J. & Zheng, J. Thermal analysis on the kinetics of thermal decomposition of FeS. J. Chongqing Univ. 34, 140–144 (2011).
Gooding, J. L. & Zolensky, M. E. Thermal stability of tochilinite. Lunar Planet. Sci. Conf. 18, 343–344 (1987).
Miller-Ricci, E., Seager, S. & Sasselov, D. The atmospheric signatures of super-Earths: how to distinguish between hydrogen-rich and hydrogen-poor atmospheres. Astrophys. J. 690, 1056–1067 (2009).
Fortney, J. J. et al. A framework for characterizing the atmospheres of low-mass low-density transiting planets. Astrophys. J. 775, 80 (2013).
Greene, T. P. et al. Characterizing transiting exoplanet atmospheres with JWST. Astrophys. J. 817, 17 (2016).
Morley, C. V., Kreidberg, L., Rustamkulov, Z., Robinson, T. & Fortney, J. J. Observing the atmospheres of known temperate Earth-sized planets with JWST. Astrophys. J. 850, 121 (2017).
Bower, D. J. et al. Linking the evolution of terrestrial interiors and an early outgassed atmosphere to astrophysical observations. Astron. Astrophys. 631, A103 (2019).
Sossi, P. A. & Fegley, B. Jr. Thermodynamics of element volatility and its application to planetary processes. Rev. Mineral. Geochem. 84, 393–459 (2018).
Operating Manual and Programming Reference: Models RGA100, RGA200, and RGA300 Residual Gas Analyzer (Stanford Research Systems, 2009).
Okumura, F. & Mimura, K. Gradual and stepwise pyrolyses of insoluble organic matter from the Murchison meteorite revealing chemical structure and isotopic distribution. Geochim. Cosmochim. Acta 75, 7063–7080 (2011).
Lindstrom, P. J. & Mallard, W. G. (eds) NIST Chemistry WebBook: NIST Standard Reference Database Number 69 (NIST, 2018).
Grady, M. M. & Wright, I. P. Elemental and isotopic abundances of carbon and nitrogen in meteorites. Space Sci. Rev. 106, 231–248 (2003).
Schaefer, L. & Fegley, B. Jr. Redox states of initial atmospheres outgassed on rocky planets and planetesimals. Astrophys. J. 843, 120 (2017).
Fegley, B. Jr. Practical Chemical Thermodynamics for Geoscientists 1st edn, Ch. 10, 482 (Elsevier Academic Press, 2013).
Court, R. W. & Sephton, M. A. Investigating the contribution of methane produced by ablating micrometeorites to the atmosphere of Mars. Earth Planet. Sci. Lett. 288, 382–385 (2009).
Huss, G. R., Lewis, R. S. & Hemkin, S. The ‘normal planetary’ noble gas component in primitive chondrites: compositions, carrier and metamorphic history. Geochim. Cosmochim. Acta 60, 3311–3340 (1996).
Abe, Y. & Matsui, T. The formation of an impact-generated H2O atmosphere and its implications for the early thermal history of the Earth. J. Geophys. Res. 90, C545–C559 (1985).
Hashimoto, G. L., Abe, Y. & Sugita, S. The chemical composition of the early terrestrial atmosphere: formation of a reducing atmosphere from CI-like material. J. Geophys. Res. Planets 112, E05010 (2007).
Schaefer, L. & Fegley, B. Jr. Outgassing of ordinary chondritic material and some of its implications for the chemistry of asteroids, planets, and satellites. Icarus 186, 462–483 (2007).
Lupu, R. E. et al. The atmospheres of Earthlike planets after giant impact events. Astrophys. J. 784, 27 (2014).
Mbarek, R. & Kempton, E. M.-R. Clouds in super-Earth atmospheres: chemical equilibrium calculations. Astrophys. J. 827, 121 (2016).
Dorn, C., Noack, L. & Rozel, A. B. Outgassing on stagnant-lid super-Earths. Astron. Astrophys. 614, A18 (2018).
Muenow, D. W., Keil, K. & McCoy, T. J. Volatiles in unequilibrated ordinary chondrites: abundances, sources and implications for explosive volcanism on differentiated asteroids. Meteoritics 30, 639–645 (1995).
Gerasimov, M. V., Ivanov, B. A., Yakovlev, O. I. & Dikov, Y. P. Physics and chemistry of impacts. Earth Moon Planets 80, 209–259 (1998).
RGA Application Bulletin #208: Spectra Reference Application Note 03/02-2/11 (MKS Instruments, 2005).
Fuchs, L. H., Olsen, E. & Jensen, K. J. Mineralogy, mineral-chemistry and composition of the Murchison (C2) meteorite. Smithsonian Contrib. Earth Sci. 10, 1–39 (1973).
Acknowledgements
We thank A. K. Skemer (UCSC) for his helpful insights, K. Kim (UCSC) for performing the preliminary XRD experiments, and L. Nittler (Carnegie Institution for Science) for helpful discussions about bulk chondrite compositions and their uncertainties. M.A.T. acknowledges support from a Achievement Rewards for College Scientists Foundation scholarship. M.T. is supported by NASA Emerging Words grant no. 80NSSC18K0498 and NASA Planetary Science Early Career Award grant no. 80NSSC20K1078. T.J. was supported by University of California Santa Cruz start-up funds.
Author information
Authors and Affiliations
Contributions
M.A.T. performed the outgassing experiments and data analysis and wrote the manuscript. M.A.T. and M.T. conceived the research. D.L., T.J., M.T. and M.A.T. collaborated to configure the experimental set-up. M.T. provided the meteorite samples used in the experiments and imparted essential guidance on the data analysis and interpretation of the results. D.L. provided the laboratory equipment for the experiments and helpful suggestions for the data analysis. T.J. helped prepare the experiments and maintain the instruments. L.S. provided the chemical equilibrium models and greatly contributed to interpreting the results and their implications. J.J.F. gave important insight into the scope of this work and its implications for exoplanet atmospheres. All authors contributed to the editing of the manuscript.
Corresponding author
Ethics declarations
Competing interests
The authors declare no competing interests.
Additional information
Peer review information Nature Astronomy thanks Paolo Sossi, Aaron Wolf and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Extended data
Extended Data Fig. 1 Data calibration steps.
Each figure illustrates the partial pressures (bars) for the molecular species measured from 200∘C to 1200∘C. Each sample’s data is calibrated by first correcting for ion fragments and atmospheric adsorption and then background subtracting. (a) is the raw mass specrometry data for the Murchison sample, (b) is the raw mass spectrometry data for the background measurement, (c) is the Murchison measurement corrected for ion fragments and atmospheric adsorption, (d) is the background measurement corrected for ion fragments and atmospheric adsorption, (e) is the Murchison measurement corrected for ion fragments and atmospheric adsorption and background-subtracted (i.e., data from (d) subtracted from data from (c)).
Extended Data Fig. 2 Results of analyzing ion fragments using a non-linear least squares regression.
The outgassing abundances in (a) are for the Murchison sample with the panel on the right side showing the average standard deviation determined from the Monte Carlo simulation for each of the species measured. The abundances in (b) are the average of the three CM chondrites.
Extended Data Fig. 3 Comparison between the yields of major volatiles released from Jbilet Winselwan samples during two identical experiments.
The partial pressure summed over temperature for each volatile species is normalized to the total pressure of released gases summed over temperature and expressed as a percentage. The uncertainty on the mean relative abundance for each volatile species is the 95 % confidence interval of the mean. The volatile yields are fairly reproducible between the two experiments, especially for the most dominant outgassed species (H2O, CO, CO2).
Extended Data Fig. 4 Comparison between the yields of major volatiles released from the samples.
The partial pressure summed over temperature for each volatile species is normalized to the total pressure of released gases summed over temperature and expressed as a percentage. The data for Winselwan is the mean of the two individual experiments conducted with the uncertainty reported as the 95 % confidence interval of the mean (see Methods and Extended Data Fig. 3). The mean relative abundance of all three samples for each volatile species is also shown with the uncertainty reported as the 95 % confidence interval of the mean. All three samples have similar outgassing abundances for the most dominant outgassing species (H2O, CO, and CO2) While H2 and H2S have larger variations up to an order of magnitude, the relative abundances for each species across the three samples are within 3σ of each other.
Extended Data Fig. 5 Additional Outgassing Species from Chemical Equilibrium Calculations.
Outgassing abundances for additional species not measured in the experiments calculated assuming chemical equilibrium for Murchison (a) and an average CM chondrite bulk composition (b) at 1E-3 Pa. The outgassing of H2O is also shown as a reference.
Supplementary information
Supplementary Information
Supplementary Figs. 1–4, Tables 1–3 and references.
Source data
Source Data Fig. 1
Excel workbook with the datasets used to generate all of the panels in Fig. 1.
Source Data Fig. 2
Excel workbook containing the data required to generate Fig. 2.
Source Data Fig. 3
Excel workbook containing the data to generate all of the panels in Fig. 3.
Source Data Fig. 4
Excel workbook containing the data to generate Fig. 4.
Source Data Extended Data Fig. 1
Excel workbook containing the data to generate all of the panels in Extended Data Fig. 1.
Source Data Extended Data Fig. 2
Excel workbook containing the data to generate Extended Data Fig. 2.
Source Data Extended Data Fig. 3
Excel workbook containing the values and uncertainties used to generate Extended Data Fig. 3.
Source Data Extended Data Fig. 4
Excel workbook containing the values and uncertainties used to generate Extended Data Fig. 4.
Source Data Extended Data Fig. 5
Excel workbook containing the data to generate Extended Data Fig. 5.
Rights and permissions
About this article
Cite this article
Thompson, M.A., Telus, M., Schaefer, L. et al. Composition of terrestrial exoplanet atmospheres from meteorite outgassing experiments. Nat Astron 5, 575–585 (2021). https://doi.org/10.1038/s41550-021-01338-8
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/s41550-021-01338-8
This article is cited by
-
Degassing of early-formed planetesimals restricted water delivery to Earth
Nature (2023)
-
Magma Ocean, Water, and the Early Atmosphere of Venus
Space Science Reviews (2023)
-
Internal dynamics of magma ocean and its linkage to atmospheres
Acta Geochimica (2022)
-
Atmospheres in the baking
Nature Astronomy (2021)