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

Nature Astronomy volume 7, pages 259–261 (2023)Cite this article

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The Original Article was published on 26 September 2022

replying to: D. E. Lalich et al. Nature Astronomy https://doi.org/10.1038/s41550-022-01775-z (2022)

In an earlier paper, however, ref. 4 explored the same model and mathematics covering the entire range of possible parameters for two and three basal CO2 ice layers. Through the quantitative analysis of 3.45 × 108 simulation results, it was demonstrated that local maxima at one of the MARSIS operating frequencies are not matched by local maxima at the other operating frequencies: that is, a layer stack producing constructive interference at one frequency does not produce the same effect at the other frequencies, which is inconsistent with MARSIS real data. Thus, constructive interference by basal layers is not a viable mechanism to explain the bright basal reflections at Ultimi Scopuli.

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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.

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Authors and Affiliations

  1. Dipartimento di Matematica e Fisica, Università degli studi Roma Tre, Rome, Italy

    Sebastian Emanuel Lauro, Elena Pettinelli, Elisabetta Mattei, Barbara Cosciotti & F. Di Paolo

  2. Centre for Astrophysics, University of Southern Queensland, Toowomba, Queensland, Australia

    Graziella Caprarelli

  3. Istituto di Radioastronomia (IRA), Istituto Nazionale di Astrofisica (INAF), Bologna, Italy

    Luca Guallini

  4. Department of Physics and Earth Sciences, Jacobs University Bremen, Bremen, Germany

    Angelo Pio Rossi

  5. Istituto di Astrofisica e Planetologia Spaziali (IAPS), Istituto Nazionale di Astrofisica (INAF), Rome, Italy

    Andrea Cicchetti, M. Cartacci & R. Noschese

  6. Istituto per il Rilevamento Elettromagnetico dell’Ambiente, Consiglio Nazionale delle Ricerche, Naples, Italy

    Francesco Soldovieri & R. Orosei

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  1. Sebastian Emanuel Lauro
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Contributions

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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