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Reply to: Explaining bright radar reflections below the south pole of Mars without liquid water

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The Original Article was published on 26 September 2022

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Fig. 1: Attenuation as a function of frequency in the SPLD.
Fig. 2: Simulation results for scenario 3.

Data availability

MARSIS data are available through the Zenodo research data repository at https://doi.org/10.5281/zenodo.1285179.

References

  1. Lalich, D. E., Hayes, A. G. & Poggiali, V. Explaining bright radar reflections below the south pole of Mars without liquid water. Nat. Astron. https://doi.org/10.1038/s41550-022-01775-z (2022).

  2. Orosei, R. et al. Radar evidence of subglacial liquid water on Mars. Science 361, 490–493 (2018).

    Article  ADS  Google Scholar 

  3. Lauro, S. E. et al. Multiple subglacial water bodies below the south pole of Mars unveiled by new MARSIS data. Nat. Astron. 5, 63–70 (2021).

    Article  ADS  Google Scholar 

  4. Orosei, R. et al. Numerical simulations of radar echoes rule out basal CO2 ice deposits at Ultimi Scopuli, Mars. Icarus 386, 115163 (2022).

    Article  Google Scholar 

  5. Pettinelli, E. et al. Frequency and time domain permittivity measurements on solid CO2 and solid CO2–soil mixtures as Martian soil simulants. J. Geophys. Res. Planets 108, E4 (2003).

    Article  Google Scholar 

  6. Smith, I. B. et al. A solid interpretation of bright radar reflectors under the Mars south polar ice. Geophys. Res. Lett. 48, e2021GL093618 (2021).

    Article  ADS  Google Scholar 

  7. Bierson, C. J., Tulaczyk, S., Courville, S. W. & Putzig, N. E. Strong MARSIS radar reflections from the base of Martian south polar cap may be due to conductive ice or minerals. Geophys. Res. Lett. 48, e2021GL093880 (2021).

    Article  ADS  Google Scholar 

  8. Schroeder, D. M. & Steinbrügge, G. Alternatives to liquid water beneath the south polar ice cap of Mars. Geophys. Res. Lett. 48, e2021GL095912 (2021).

    Article  ADS  Google Scholar 

  9. Mattei, E. et al. Assessing the role of clay and salts on the origin of MARSIS basal bright reflections. Earth Planet. Sci. Lett. 579, 117370 (2022).

    Article  Google Scholar 

  10. Arnold, N. S. et al. Modeled subglacial water flow routing supports localized intrusive heating as a possible cause of basal melting of Mars’ south polar ice cap. J. Geophys. Res. Planets 124, 2101–2116 (2019).

    Article  ADS  Google Scholar 

  11. Kolb, E. J. & Tanaka, K. L. Geologic history of the polar regions of Mars based on Mars global surveyor data. II. Amazonian period. Icarus 154, 22–39 (2001).

    Article  ADS  Google Scholar 

  12. Barker, E., Schorn, R., Woszczyk, A., Tull, R. & Little, S. Mars: detection of atmospheric water vapor during the southern hemisphere spring and summer season. Science 170, 1308–1310 (1970).

    Article  ADS  Google Scholar 

  13. Kieffer, H. H. Mars south polar spring and summer temperatures: a residual CO2 frost. J. Geophys. Res. 84, 8263–8288 (1979).

    Article  ADS  Google Scholar 

  14. Titus, T. N., Kieffer, H. H. & Christensen, P. R. Exposed water ice discovered near the south pole of Mars. Science 299, 1048–1051 (2003).

    Article  ADS  Google Scholar 

  15. Bibring, J. P. et al. Perennial water ice identified in the south polar cap of Mars. Nature 428, 627–630 (2004).

    Article  ADS  Google Scholar 

  16. Byrne, S. The polar deposits of Mars. Annu. Rev. Earth Planet. Sci. 37, 535–560 (2009).

    Article  ADS  Google Scholar 

  17. Byrne, S. & Ingersoll, A. P. Martian climatic events on timescales of centuries: evidence from feature morphology in the residual south polar ice cap. Geophys. Res. Lett. 30, 1696 (2003).

    Article  ADS  Google Scholar 

  18. Tokar, R. L. et al. Mars Odissey neutron sensing of the south polar cap. Geophys. Res. Lett. 30, 1677 (2003).

    Article  ADS  Google Scholar 

  19. Clifford, S. M. et al. The state and future of Mars polar science and exploration. Icarus 144, 210–242 (2000).

    Article  ADS  Google Scholar 

  20. Smith, D. E. et al. Mars Orbiter Laser Altimeter: experiment summary after the first year of global mapping of Mars. J. Geophys. Res. 106, 23689–23722 (2001).

    Article  ADS  Google Scholar 

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All authors equally contributed to the discussion and the data analysis; S.E.L., E.P., G.C., E.M., B.C., F.S. and R.O. wrote and revised the manuscript.

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Correspondence to Elena Pettinelli.

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Lauro, S.E., Pettinelli, E., Caprarelli, G. et al. Reply to: Explaining bright radar reflections below the south pole of Mars without liquid water. Nat Astron 7, 259–261 (2023). https://doi.org/10.1038/s41550-022-01871-0

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