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The language of exoplanet ranking metrics needs to change

We have found many Earth-sized worlds but we have no way of determining if their surfaces are Earth-like. This makes it impossible to quantitatively compare habitability, and pretending we can risks damaging the field.

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  1. 1

    NASA Exoplanet Archive (California Institute of Technology, 2017);

  2. 2

    Seager, S., Schrenk, M. & Bains, W. Astrobiology 12, 61–82 (2012)

    Article  ADS  Google Scholar 

  3. 3

    Joshi, M. M., Haberle, R. M. & Reynolds, R. T. Icarus 129, 450–465 (1997)

    Article  ADS  Google Scholar 

  4. 4

    Williams, D. M. & Pollard, D. Int. J. Astrobiol. 1, 61 (2002)

    Article  Google Scholar 

  5. 5

    Rogers, L. A. Astrophys. J. 801, 41 (2015)

    Article  ADS  Google Scholar 

  6. 6

    Dorn, C. et al. Astron. Astrophys. 577, A83 (2015)

    Article  Google Scholar 

  7. 7

    Schulze-Makuch, D. & Guinan, E. Astrobiology 16, 817–821 (2016)

    Article  ADS  Google Scholar 

  8. 8

    Kasting, J. F., Whitmire, D. P. & Reynolds, R. T. Icarus 101, 108–128 (1993)

    Article  ADS  Google Scholar 

  9. 9

    Barnes, R., Meadows, V. S. & Evans, N. Astrophys. J. 814, 91 (2015)

    Article  ADS  Google Scholar 

  10. 10

    Schulze-Makuch, D. et al. Astrobiology 11, 1041–1052 (2011)

    Article  ADS  Google Scholar 

Download references

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Correspondence to Elizabeth Tasker.

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Tasker, E., Tan, J., Heng, K. et al. The language of exoplanet ranking metrics needs to change. Nat Astron 1, 0042 (2017).

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