The DOI matches its Crossref record; 24 of the 24 references it cites were found in a registry or an index.
Water Activity and the Challenge for Life on Early Mars
Abstract
In situ and orbital exploration of the martian surface has shown that acidic, saline liquid water was intermittently available on ancient Mars. The habitability of these waters depends critically on water activity ( \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(a_{\mathrm{H}_{2}\mathrm{O}}\) \end{document} ), a thermodynamic measure of salinity, which, for terrestrial organisms, has sharply defined limits. Using constraints on fluid chemistry and saline mineralogy based on martian data, we calculated the maximum \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(a_{\mathrm{H}_{2}\mathrm{O}}\) \end{document} for Meridiani Planum and other environments where salts precipitated from martian brines. Our calculations indicate that the salinity of well-documented surface waters often exceeded levels tolerated by known terrestrial organisms.
Overview
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Integrity signals
Registry
Cites
Statistics
Verification
Claims the paper makes
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
The self-check needs the paper’s full text.
Citations
Cites
Sulfates in Martian Layered Terrains: The OMEGA/Mars Express View
Gendrin, A., Mangold, N., Bibring, J.-P., Langevin, Y., Gondet, B., Poulet, F., Bonello, G., Quantin, C., Mustard, J., Arvidson, R., et al. (2005) · Science · doi:10.1126/science.1109087 · Cited by 986
In Situ Evidence for an Ancient Aqueous Environment at Meridiani Planum, Mars
Squyres, S. W., Grotzinger, J. P., Arvidson, R. E., Bell, J. F., Calvin, W., Christensen, P. R., Clark, B. C., Crisp, J. A., Farrand, W. H., Herkenhoff, K. E., et al. (2004) · Science · doi:10.1126/science.1104559 · Cited by 968
Self-citationJarosite and Hematite at Meridiani Planum from Opportunity's Mössbauer Spectrometer
Klingelhöfer, G., Morris, R. V., Bernhardt, B., Schröder, C., Rodionov, D. S., de Souza, P. A., Yen, A., Gellert, R., Evlanov, E. N., Zubkov, B., et al. (2004) · Science · doi:10.1126/science.1104653 · Cited by 826
Diversity of halophilic microorganisms: Environments, phylogeny, physiology, and applications
Oren, A. (2002) · Journal of Industrial Microbiology & Biotechnology · doi:10.1038/sj.jim.7000176 · Cited by 803
Provenance and diagenesis of the evaporite-bearing Burns formation, Meridiani Planum, Mars
McLennan, S. M., Bell, J. F., Calvin, W. M., Christensen, P. R., Clark, B. C., de Souza, P. A., Farmer, J., Farrand, W. H., Fike, D. A., Gellert, R., et al. (2005) · Earth and Planetary Science Letters · doi:10.1016/j.epsl.2005.09.041 · Cited by 571
Self-citationGrotzinger, J. P., Arvidson, R. E., Bell, J. F., Calvin, W., Clark, B. C., Fike, D. A., Golombek, M., Greeley, R., Haldemann, A., Herkenhoff, K. E., et al. (2005) · Earth and Planetary Science Letters · doi:10.1016/j.epsl.2005.09.039 · Cited by 569
Self-citationGrant, W. D. (2004) · Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences · doi:10.1098/rstb.2004.1502 · Cited by 531
Chloride-Bearing Materials in the Southern Highlands of Mars
Osterloo, M. M., Hamilton, V. E., Bandfield, J. L., Glotch, T. D., Baldridge, A. M., Christensen, P. R., Tornabene, L. L., & Anderson, F. S. (2008) · Science · doi:10.1126/science.1150690 · Cited by 464
Chemistry and mineralogy of outcrops at Meridiani Planum
Clark, B. C., Morris, R. V., McLennan, S. M., Gellert, R., Jolliff, B., Knoll, A. H., Squyres, S. W., Lowenstein, T. K., Ming, D. W., Tosca, N. J., et al. (2005) · Earth and Planetary Science Letters · doi:10.1016/j.epsl.2005.09.040 · Cited by 400
Self-citationMing, D. W., Mittlefehldt, D. W., Morris, R. V., Golden, D. C., Gellert, R., Yen, A., Clark, B. C., Squyres, S. W., Farrand, W. H., Ruff, S. W., et al. (2006) · Journal of Geophysical Research: Planets · doi:10.1029/2005je002560 · Cited by 299
Cited by
A Habitable Fluvio-Lacustrine Environment at Yellowknife Bay, Gale Crater, Mars
Grotzinger, J. P., Sumner, D. Y., Kah, L. C., Stack, K., Gupta, S., Edgar, L., Rubin, D., Lewis, K., Schieber, J., Mangold, N., et al. (2014) · Science · doi:10.1126/science.1242777 · Cited by 901
Self-citationOrbital Identification of Carbonate-Bearing Rocks on Mars
Ehlmann, B. L., Mustard, J. F., Murchie, S. L., Poulet, F., Bishop, J. L., Brown, A. J., Calvin, W. M., Clark, R. N., Marais, D. J. D., Milliken, R. E., et al. (2008) · Science · doi:10.1126/science.1164759 · Cited by 713
Elemental proxies for paleosalinity analysis of ancient shales and mudrocks
Wei, W., & Algeo, T. J. (2020) · Geochimica et Cosmochimica Acta · doi:10.1016/j.gca.2019.06.034 · Cited by 677
Geologic context of proposed chloride‐bearing materials on Mars
Osterloo, M. M., Anderson, F. S., Hamilton, V. E., & Hynek, B. M. (2010) · Journal of Geophysical Research: Planets · doi:10.1029/2010je003613 · Cited by 274
Juvenile chemical sediments and the long term persistence of water at the surface of Mars
Tosca, N. J., & Knoll, A. H. (2009) · Earth and Planetary Science Letters · doi:10.1016/j.epsl.2009.07.004 · Cited by 160
Self-citation
Metadata
- Authors
- Tosca, N. J., Knoll, A. H., & McLennan, S. M.
- Venue
- Science
- Published
- 2008-05-30
- Volume
- 320
- Issue
- 5880
- Pages
- 1204-1207
- ISSN
- 0036-8075 (ISSN-L)
- 1095-9203
- OpenAlex
- W2117779704
- Cited by
- 264
- References
- 24
- FWCI
- 13.36
- Type
- journal article
- Language
- en
- Open access
- closed
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
How to cite
Cite CoChat for the checks on this page, and the paper for its own findings.
- This page
- CoChat. (2026). Citation check: Water Activity and the Challenge for Life on Early Mars. https://app.cochat.ai/papers/10.1126/science.1155432
- The paper
- Tosca, N. J., Knoll, A. H., & McLennan, S. M. (2008). Water Activity and the Challenge for Life on Early Mars. Science. https://doi.org/10.1126/science.1155432
Data sources
Bibliographic data: Semantic Scholar, OpenAlex, Crossref.
Contains information from the Semantic Scholar Academic Graph Datasets, made available under the ODC Attribution License (ODC-BY 1.0).
Semantic Scholar’s data is described in: Kinney, R., et al. (2023). The Semantic Scholar Open Data Platform. arXiv:2301.10140.
