Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

A nitrogen-rich atmosphere on ancient Mars consistent with isotopic evolution models

Nature Geoscience volume 15, pages 106–111 (2022)Cite this article

Subjects

Abstract

The ratio of nitrogen isotopes in the Martian atmosphere is a key constraint on the planet’s atmospheric evolution. However, enrichment of the heavy isotope expected due to atmospheric loss from sputtering and photochemical processes is greater than measurements. A massive, multi-bar early CO2-dominated atmosphere and recent volcanic outgassing have been proposed to explain this discrepancy, and many previous models have assumed atmospheric nitrogen rapidly reached a steady state where loss to space balanced volcanic outgassing. Here we show using time-dependent models that the abundance and isotopic composition of nitrogen in the Martian atmosphere can be explained by a family of evolutionary scenarios in which the initial partial pressure of nitrogen is sufficiently high that a steady state is not reached and nitrogen levels gradually decline to present-day values over 4 billion years. Our solutions do not require a multi-bar early CO2 atmosphere and are consistent with volcanic outgassing indicated by both geologic mapping and the atmospheric 36Ar/38Ar ratio. Monte Carlo simulations that include these scenarios estimate that the partial pressure of N2 was 60–740 mbar (90% confidence, with a median value of 310 mbar) at 3.8 billion years ago when the valley networks formed. We suggest that such a high nitrogen partial pressure could have contributed substantially to warming on early Mars.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Bifurcation in the evolution of nitrogen between the steady-state scenarios and the dynamical scenarios.
Fig. 2: Example of the steady-state and dynamical solutions consistent with the size and isotopic composition of Mars’s nitrogen reservoir.
Fig. 3: Randomly selected solutions from the constrained and the unconstrained MCMCs.

Similar content being viewed by others

Data availability

The data needed to generate all figures in the main text (Figs. 1–3) and Extended Data Figs. 2 and 3 are publicly available at Zenodo (https://doi.org/10.5281/zenodo.5760095).

Code availability

The source code of the nitrogen evolution model and the associated configuration files used in this study are publicly available at Zenodo (https://doi.org/10.5281/zenodo.5760095).

References

  1. Fassett, C. I. & Head, J. W. Sequence and timing of conditions on early Mars. Icarus 211, 1204–1214 (2011).

    Article  Google Scholar 

  2. Robbins, S. J., Hynek, B. M., Lillis, R. J. & Bottke, W. F. Large impact crater histories of Mars: the effect of different model crater age techniques. Icarus 225, 173–184 (2013).

    Article  Google Scholar 

  3. Mathew, K. & Marti, K. Early evolution of Martian volatiles: nitrogen and noble gas components in ALH84001 and Chassigny. J. Geophys. Res. Planets 106, 1401–1422 (2001).

    Article  Google Scholar 

  4. Wong, M. H. et al. Isotopes of nitrogen on Mars: atmospheric measurements by Curiosity’s mass spectrometer. Geophys. Res. Lett. 40, 6033–6037 (2013).

    Article  Google Scholar 

  5. McElroy, M. B. & Yung, Y. L. Isotopic composition of the Martian atmosphere. Science 194, 68–70 (1976).

    Article  Google Scholar 

  6. McElroy, M. B., Yung, Y. L. & Nier, A. O. Isotopic composition of nitrogen: implications for the past history of Mars’ atmosphere. Science 194, 70–72 (1976).

    Article  Google Scholar 

  7. Fox, J. L. & Dalgarno, A. Nitrogen escape from Mars. J. Geophys. Res. Space Phys. 88, 9027–9032 (1983).

    Article  Google Scholar 

  8. Fox, J. L. The production and escape of nitrogen atoms on Mars. J. Geophys. Res. Planets 98, 3297–3310 (1993).

    Article  Google Scholar 

  9. Jakosky, B. M., Pepin, R. O., Johnson, R. E. & Fox, J. L. Mars atmospheric loss and isotopic fractionation by solar-wind-induced sputtering and photochemical escape. Icarus 111, 271–288 (1994).

    Article  Google Scholar 

  10. Zent, A. P. & McKay, C. P. The chemical reactivity of the Martian soil and implications for future missions. Icarus 108, 146–157 (1994).

    Article  Google Scholar 

  11. Fox, J. L. & Hać, A. The 15N/14N isotope fractionation in dissociative recombination of N2+. J. Geophys. Res. Planets 102, 9191–9204 (1997).

    Article  Google Scholar 

  12. Kurokawa, H., Kurosawa, K. & Usui, T. A lower limit of atmospheric pressure on early Mars inferred from nitrogen and argon isotopic compositions. Icarus 299, 443–459 (2018).

    Article  Google Scholar 

  13. Stern, J. C. et al. Evidence for indigenous nitrogen in sedimentary and Aeolian deposits from the Curiosity rover investigations at Gale Crater. Mars. Proc. Natl Acad. Sci. USA 112, 4245–4250 (2015).

    Article  Google Scholar 

  14. Sutter, B. et al. Evolved gas analyses of sedimentary rocks and eolian sediment in Gale Crater, Mars: results of the Curiosity rover’s sample analysis at Mars instrument from Yellowknife Bay to the Namib Dune. J. Geophys. Res. Planets 122, 2574–2609 (2017).

    Article  Google Scholar 

  15. Slipski, M. & Jakosky, B. M. Argon isotopes as tracers for Martian atmospheric loss. Icarus 272, 212–227 (2016).

    Article  Google Scholar 

  16. Hu, R., Kass, D. M., Ehlmann, B. L. & Yung, Y. L. Tracing the fate of carbon and the atmospheric evolution of Mars. Nat. Commun. 6, 10003 (2015).

    Article  Google Scholar 

  17. Song, Y. et al. Quantum-state dependence of product branching ratios in vacuum ultraviolet photodissociation of N2. Astrophys. J. 819, 23 (2016).

    Article  Google Scholar 

  18. Jakosky, B. M. et al. Loss of the Martian atmosphere to space: present-day loss rates determined from MAVEN observations and integrated loss through time. Icarus 315, 146–157 (2018).

    Article  Google Scholar 

  19. Jakosky, B. M. The CO2 inventory on Mars. Planet. Space Sci. 175, 52–59 (2019).

    Article  Google Scholar 

  20. Forget, F. et al. 3d modelling of the early Martian climate under a denser CO2 atmosphere: temperatures and CO2 ice clouds. Icarus 222, 81–99 (2013).

    Article  Google Scholar 

  21. von Paris, P., Grenfell, J. L., Rauer, H. & Stock, J. W. N2-associated surface warming on early Mars. Planet. Space Sci. 82, 149–154 (2013).

    Article  Google Scholar 

  22. Leblanc, F. & Johnson, R. Role of molecular species in pickup ion sputtering of the Martian atmosphere. J. Geophys. Res. Planets https://doi.org/10.1029/2000JE001473 (2002).

  23. Jakosky, B. M. et al. Mars’ atmospheric history derived from upper-atmosphere measurements of 38Ar/36Ar. Science 355, 1408–1410 (2017).

    Article  Google Scholar 

  24. McKay, C. P. & Stoker, C. R. The early environment and its evolution on Mars: implication for life. Rev. Geophysics 27, 189–214 (1989).

    Article  Google Scholar 

  25. Marty, B. & Dauphas, N. The nitrogen record of crust–mantle interaction and mantle convection from Archean to present. Earth Planet. Sci. Lett. 206, 397–410 (2003).

    Article  Google Scholar 

  26. Hirschmann, M. M. & Withers, A. C. Ventilation of CO2 from a reduced mantle and consequences for the early Martian greenhouse. Earth Planet. Sci. Lett. 270, 147–155 (2008).

    Article  Google Scholar 

  27. Bergin, E. A., Blake, G. A., Ciesla, F., Hirschmann, M. M. & Li, J. Tracing the ingredients for a habitable Earth from interstellar space through planet formation. Proc. Natl Acad. Sci. USA 112, 8965–8970 (2015).

    Article  Google Scholar 

  28. Tian, F., Kasting, J. F. & Solomon, S. C. Thermal escape of carbon from the early Martian atmosphere. Geophys. Res. Lett. 36, L02205 (2009).

    Article  Google Scholar 

  29. Marty, B. The origins and concentrations of water, carbon, nitrogen and noble gases on Earth. Earth Planet. Sci. Lett. 313, 56–66 (2012).

    Article  Google Scholar 

  30. Ramirez, R. M. et al. Warming early Mars with CO2 and H2. Nat. Geosci. 7, 59–63 (2014).

    Article  Google Scholar 

  31. Kite, E. S. et al. Methane bursts as a trigger for intermittent lake-forming climates on post-Noachian Mars. Nat. Geosci. 10, 737–740 (2017).

    Article  Google Scholar 

  32. Wordsworth, R. et al. Transient reducing greenhouse warming on early Mars. Geophys. Res. Lett. 44, 665–671 (2017).

    Article  Google Scholar 

  33. Grotzinger, J. et al. Deposition, exhumation, and paleoclimate of an ancient lake deposit, Gale Crater, Mars. Science 350, aac7575 (2015).

    Article  Google Scholar 

  34. Zent, A., Quinn, R. & Jakosky, B. Fractionation of nitrogen isotopes on Mars: the role of the regolith as a buffer. Icarus 112, 537–540 (1994).

    Article  Google Scholar 

  35. Ballou, E. V., Wood, P. C., Wydeven, T., Lehwalt, M. E. & Mack, R. E. Chemical interpretation of Viking Lander 1 life detection experiment. Nature 271, 644–645 (1978).

    Article  Google Scholar 

  36. Nakamura, T. & Tajika, E. Climate change of Mars-like planets due to obliquity variations: implications for Mars. Geophys. Res. Lett. 30, 1685 (2003).

    Article  Google Scholar 

  37. Soto, A., Mischna, M., Schneider, T., Lee, C. & Richardson, M. Martian atmospheric collapse: idealized GCM studies. Icarus 250, 553–569 (2015).

    Article  Google Scholar 

  38. Ribas, I., Guinan, E. F., Güdel, M. & Audard, M. Evolution of the solar activity over time and effects on planetary atmospheres. I. High-energy irradiances (1-1700 Å). Astrophys. J. 622, 680 (2005).

    Article  Google Scholar 

  39. Claire, M. W. et al. The evolution of solar flux from 0.1 nm to 160 μm: quantitative estimates for planetary studies. Astrophys. J. 757, 95 (2012).

    Article  Google Scholar 

  40. Tu, L., Johnstone, C. P., Güdel, M. & Lammer, H. The extreme ultraviolet and X-ray Sun in time: high-energy evolutionary tracks of a solar-like star. Astron. Astrophys. 577, L3 (2015).

    Article  Google Scholar 

  41. Bakalian, F. Production of hot nitrogen atoms in the Martian thermosphere. Icarus 183, 69–78 (2006).

    Article  Google Scholar 

  42. Bakalian, F. & Hartle, R. E. Monte Carlo computations of the escape of atomic nitrogen from Mars. Icarus 183, 55–68 (2006).

    Article  Google Scholar 

  43. Cui, J., Wu, X.-S., Gu, H., Jiang, F.-Y. & Wei, Y. Photochemical escape of atomic C and N on Mars: clues from a multi-instrument MAVEN dataset. Astron. Astrophys. 621, A23 (2019).

    Article  Google Scholar 

  44. Lillis, R., Frey, H. & Manga, M. Rapid decrease in Martian crustal magnetization in the Noachian era: implications for the dynamo and climate of early Mars. Geophys. Res. Lett. 35, L14203 (2008).

    Article  Google Scholar 

  45. Luhmann, J., Johnson, R. & Zhang, M. Evolutionary impact of sputtering of the Martian atmosphere by O+ pickup ions. Geophys. Res. Lett. 19, 2151–2154 (1992).

    Article  Google Scholar 

  46. Fang, X. et al. The importance of pickup oxygen ion precipitation to the Mars upper atmosphere under extreme solar wind conditions. Geophys. Res. Lett. 40, 1922–1927 (2013).

    Article  Google Scholar 

  47. Wang, Y.-C. et al. Statistical studies on Mars atmospheric sputtering by precipitating pickup O+: preparation for the MAVEN mission. J. Geophys. Res. Planets 120, 34–50 (2015).

    Article  Google Scholar 

  48. Leblanc, F. et al. Mars heavy ion precipitating flux as measured by Mars atmosphere and volatile evolution. Geophys. Res. Lett. 42, 9135–9141 (2015).

    Article  Google Scholar 

  49. Leblanc, F. & Johnson, R. Sputtering of the Martian atmosphere by solar wind pick-up ions. Planet. Space Sci. 49, 645–656 (2001).

    Article  Google Scholar 

  50. Barabash, S., Fedorov, A., Lundin, R. & Sauvaud, J.-A. Martian atmospheric erosion rates. Science 315, 501–503 (2007).

    Article  Google Scholar 

  51. Jakosky, B. M. et al. MAVEN observations of the response of Mars to an interplanetary coronal mass ejection. Science 350, aad0210 (2015).

    Article  Google Scholar 

  52. Curry, S. et al. Observations of ICMEs at Mars: past and present. AGU Fall Meeting Abstracts 2018, P51H–-2971 (2018).

    Google Scholar 

  53. Ma, Y.-J. & Nagy, A. F. Ion escape fluxes from Mars. Geophys. Res. Lett. 34, L08201 (2007).

    Article  Google Scholar 

  54. Manning, C. V., Ma, Y., Brain, D. A., McKay, C. P. & Zahnle, K. J. Parametric analysis of modeled ion escape from Mars. Icarus 212, 131–137 (2011).

    Article  Google Scholar 

  55. Bougher, S. et al. Early MAVEN deep dip campaign reveals thermosphere and ionosphere variability. Science 350, aad0459 (2015).

    Article  Google Scholar 

  56. Grott, M., Morschhauser, A., Breuer, D. & Hauber, E. Volcanic outgassing of CO2 and H2O on Mars. Earth Planet. Sci. Lett. 308, 391–400 (2011).

    Article  Google Scholar 

  57. Greeley, R. & Schneid, B. D. Magma generation on Mars: amounts, rates, and comparisons with Earth, Moon, and Venus. Science 254, 996–998 (1991).

    Article  Google Scholar 

  58. Phillips, R. J. et al. Ancient geodynamics and global-scale hydrology on Mars. Science 291, 2587–2591 (2001).

    Article  Google Scholar 

  59. Tanaka, K. L., Robbins, S., Fortezzo, C., Skinner, J. Jr. & Hare, T. M. The digital global geologic map of Mars: chronostratigraphic ages, topographic and crater morphologic characteristics, and updated resurfacing history. Planet. Space Sci. 95, 11–24 (2014).

    Article  Google Scholar 

  60. Bouley, S., Baratoux, D., Paulien, N., Missenard, Y. & Saint-Bézar, B. The revised tectonic history of Tharsis. Earth Planet. Sci. Lett. 488, 126–133 (2018).

    Article  Google Scholar 

  61. Werner, S. C. The global Martian volcanic evolutionary history. Icarus 201, 44–68 (2009).

    Article  Google Scholar 

  62. Gelman, A. et al. Inference from iterative simulation using multiple sequences. Stat. Sci. 7, 457–472 (1992).

    Article  Google Scholar 

  63. Laskar, J. et al. Long term evolution and chaotic diffusion of the insolation quantities of Mars. Icarus 170, 343–364 (2004).

    Article  Google Scholar 

  64. Manning, C. V., McKay, C. P. & Zahnle, K. J. The nitrogen cycle on Mars: impact decomposition of near-surface nitrates as a source for a nitrogen steady state. Icarus 197, 60–64 (2008).

    Article  Google Scholar 

  65. Werner, S. & Tanaka, K. Redefinition of the crater-density and absolute-age boundaries for the chronostratigraphic system of Mars. Icarus 215, 603–607 (2011).

    Article  Google Scholar 

  66. Ivanov, B. A. Mars/Moon cratering rate ratio estimates. Space Sci. Rev. 96, 87–104 (2001).

    Article  Google Scholar 

  67. Hartmann, W. K. Martian cratering 8: isochron refinement and the chronology of Mars. Icarus 174, 294–320 (2005).

    Article  Google Scholar 

Download references

Acknowledgements

We thank Y. L. Yung, B. Ehlmann, B. Jakosky, H. Kurokawa, C. Manning, R. Johnson, M. Grott, F. Gaillard, M. Slipski and C.-Y. Ng for helpful discussions. This work was supported by NASA Habitable Worlds grant NNN13D466T, later changed to 80NM0018F0612. The research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

Author information

Authors and Affiliations

  1. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA

    Renyu Hu & Trent B. Thomas

  2. Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA

    Renyu Hu

  3. Department of Earth and Space Sciences/Astrobiology Program, University of Washington, Seattle, WA, USA

    Trent B. Thomas

Authors
  1. Renyu Hu
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Trent B. Thomas
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

R.H. designed the study and the evolution model, interpreted the results and wrote the manuscript. T.B.T. implemented the evolution model, carried out the simulations and interpreted the results.

Corresponding author

Correspondence to Renyu Hu.

Ethics declarations

Competing interests

The authors declare no competing interests.

Peer review

Peer review information

Nature Geoscience thanks Ramses Ramirez and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. Primary Handling Editors: Tamara Goldin; Xujia Jiang; Stefan Lachowycz.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data

Extended Data Fig. 1 A model for the long-term evolution of the free nitrogen reservoir on Mars.

The free nitrogen reservoir is comprised of N2 adsorbed in the regolith and 2 in the atmosphere, and it changes over time due to sputtering loss, photochemical loss, ion loss, volcanic outgassing, and nitrate deposition. The regolith and the atmosphere are assumed to exchange isotopes over geologic timescales driven by the temperature variations due to orbital obliquity changes63. We do not include impact additions or removal because the major impacts should have occurred before the modeled period1,2 (from 3.8 Ga to present). Nor do we include the impact decomposition of near-surface nitrates64 explicitly, as its rate is less than the present-day outgassing and photochemical escape rates by several orders of magnitude (Supplementary Information H).

Extended Data Fig. 2 Representative background CO2 evolutionary scenarios adopted in this study.

These scenarios are selected from the evolutionary tracks of CO2 derived in Hu et al. (2015)16 and they are consistent with the present-day pressure and carbon isotopic composition. Scenarios 1 - 3 assume that the photochemical loss rate of carbon depends on the Sun’s Lyman continuum flux to the power of 2. Scenario 1 assumes that carbonate deposition of 40 mbar occurred throughout the Noachian and Hesperian (that is, till 3.0 Ga) in shallow subsurface aquifers. This represents the lower bound of the initial CO2 partial pressure. Scenarios 2 and 3 assume that carbonate deposition of 290 and 600 mbar occurred in the Noachian and early Hesperian (that is, till 3.5 Ga) in open-water systems. Scenario 3 has an initial CO2 partial pressure of 1 bar and is the default scenario adopted in this study. Scenario 4 assumes a power-law index of 3, and that carbonate deposition of 1400 mbar occurred in the Noachian and early Hesperian (that is, till 3.5 Ga) in open-water systems. This represents the upper bound of the initial CO2 partial pressure. Scenario 5 is an endmember scenario where the CO2 atmosphere is assumed to be collapsed at all times and the pressure constant at 7 mbar.

Extended Data Fig. 3 Baseline crustal production rate adopted in this study.

(a) Crustal production rates derived from the photogeologic analysis of volcanic provinces57 from 3.8 Ga. To convert the photogeological analysis (expressed as the total volcanic emplacement in each geologic period from middle Noachian to late Amazonian) to the crustal production rate, we compare the rates derived using the age boundaries from the crater density65 and the chronology model of Ivanov (2001)66 and Hartmann (2005)67, as well as interpolation methods using either step functions or mid-point averages. The labels show the total volcanic activity and the integrated volcanic activity in the last 2 billion years (in parentheses). The midpoint approach would introduce substantially more total volcanism, and so we use the step-function approach. Also in comparison is a volcanic history derived from earlier photogeologic analyses and used in the recent argon isotope study15. The step-function approach on the Hartmann (2015) chronology leads to a baseline model that is very similar to the one used in the argon isotope study15 in terms of the total and the recent volcanic rates. (b) Baseline crustal production rate adopted in this work, based on the global thermal evolution model56 and the step-function interpolation of the photogeologic analysis of volcanic provinces57, whichever is greater. We adopt the model using the Hartmann (2015) chronology as our baseline model, and consider the one using the Ivanov (2001) chronology as the variant. The two models have appreciable difference in the last 2 billion years.

Extended Data Fig. 4 Posterior distributions of parameters from unconstrained MCMC simulations with the parameters and their boundaries listed in Table 1.

The MCMC simulations adopt the five representative CO2 evolution scenarios shown in Extended Data Fig. 2.

Extended Data Fig. 5 Posterior distributions of parameters from constrained MCMC simulations with the parameters and their boundaries listed in Table 1.

The MCMC simulations adopt the five representative CO2 evolution scenarios in Extended Data Fig. 2.

Extended Data Fig. 6 Posterior distributions of parameters from constrained MCMC simulations that fix the sputtering multiplier to be fsp=0.5, 1, and 2.

These simulations adopt the CO2 evolutionary scenario No. 3 with the initial partial pressure of 1.0 bar as shown in Extended Data Fig. 2. The initial partial pressure of N2 is more tightly constrained when the sputtering multiplier is fixed.

Supplementary information

Supplementary Information

Supplementary Information A–H, figures and tables.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Hu, R., Thomas, T.B. A nitrogen-rich atmosphere on ancient Mars consistent with isotopic evolution models. Nat. Geosci. 15, 106–111 (2022). https://doi.org/10.1038/s41561-021-00886-y

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41561-021-00886-y

This article is cited by

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing