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.

Geoscience

Fossil raindrops and ancient air

Nature volume 484, pages 322–324 (2012)Cite this article

Subjects

An analysis of fossil imprints of ancient raindrops suggests that the density of the atmosphere 2.7 billion years ago was much the same as that today. This result casts fresh light on a long-standing palaeoclimate paradox. See Letter p.359

When a main-sequence star such as our Sun ages, its inner core becomes denser and the temperature at which its hydrogen is fused to helium increases. As a result, the Sun is currently more luminous, and delivers more energy to Earth's surface, than in the past — its energy output around 2billion years ago is inferred1 to have been less than 85% of that today. Such a faint Sun should not have been able to warm Earth's surface above the freezing point of water2, yet the geological record indicates that liquid water abounded at that time. The apparent contradiction between theory (sub-freezing Earth surface temperatures) and observation (liquid water) is known as the 'faint young Sun' paradox. On page 359 of this issue, Som et al.3 address this paradox using seemingly unlikely evidence: fossilized imprints left by ancient raindrops.Footnote 1

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

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

Learn more

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

Figure 1: Solid evidence.

W. ALTERMANN/UNIV. PRETORIA

Notes

  1. *This article and the paper under discussion3 were published online on 28 March 2012.

References

  1. Ribas, I. in Solar and Stellar Variability: Impact on Earth and Planets (eds Kosovichev, A. G., Andrei, A. H. & Rozelot, J.-P.) Ch. 1 (Cambridge Univ. Press, 2010).

    Google Scholar 

  2. Sagan, C. & Mullen, G. Science 177, 52–56 (1972).

    Article  ADS  CAS  Google Scholar 

  3. Som, S. M., Catling, D. C., Harnmeijer, J. P., Polivka, P. M. & Buick, R. Nature 484, 359–362 (2012).

    Article  ADS  CAS  Google Scholar 

  4. Ramsay, J. G. Trans. Geol. Soc. S. Afr. 66, 353–401 (1963).

    Google Scholar 

  5. Schopf, J. W. & Barghoorn, E. S. Science 156, 508–512 (1967).

    Article  ADS  CAS  Google Scholar 

  6. Harrison, T. M. Annu. Rev. Earth Planet. Sci. 37, 479–505 (2009).

    Article  ADS  CAS  Google Scholar 

  7. Reinhard, C. T. & Planavsky, N. J. Nature 474, http://dx.doi.org/10.1038/nature09959 (2011).

  8. Dauphas, N. & Kasting, J. F. Nature 474, http://dx.doi.org/10.1038/nature09960 (2011).

  9. Goldblatt, C. & Zahnle, K. J. Nature 474, http://dx.doi.org/10.1038/nature09961 (2011).

  10. Rosing, M. T., Bird, D. K., Sleep, N. H. & Bjerrum, C. J. Nature 474, http://dx.doi.org/10.1038/nature09962 (2011).

  11. Lyell, C. Edinb. N. Phil. J. 51, 70–74 (1851).

    Google Scholar 

  12. Kasting, J. F. Precambr. Res. 34, 205–229 (1987).

    Article  ADS  CAS  Google Scholar 

  13. Goldblatt, C. et al. Nature Geosci. 2, 891–896 (2009).

    Article  ADS  CAS  Google Scholar 

  14. Sheldon, N. D. Precambr. Res. 147, 148–155 (2006).

    Article  ADS  CAS  Google Scholar 

  15. Haqq-Misra, J. D., Domagal-Goldman, S. D., Kasting, P. J. & Kasting, J. F. Astrobiology 8, 1127–1137 (2008).

    Article  ADS  CAS  Google Scholar 

  16. Ueno, Y. et al. Proc. Natl Acad. Sci. USA 106, 14784–14789 (2009).

    Article  ADS  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. William S. Cassata and Paul R. Renne are in the Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, California 94720, USA, and at the Berkeley Geochronology Center.,

    William S. Cassata & Paul R. Renne

Authors
  1. William S. Cassata
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Paul R. Renne
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding authors

Correspondence to William S. Cassata or Paul R. Renne.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Cassata, W., Renne, P. Fossil raindrops and ancient air. Nature 484, 322–324 (2012). https://doi.org/10.1038/nature11036

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature11036

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