Skip to main content

On the probability of habitable planets

  • François Forget (a1)

In the past 15 years, astronomers have revealed that a significant fraction of the stars should harbour planets and that it is likely that terrestrial planets are abundant in our galaxy. Among these planets, how many are habitable, i.e. suitable for life and its evolution? These questions have been discussed for years and we are slowly making progress. Liquid water remains the key criterion for habitability. It can exist in the interior of a variety of planetary bodies, but it is usually assumed that liquid water at the surface interacting with rocks and light is necessary for emergence of a life able to modify its environment and evolve. The first key issue is thus to understand the climatic conditions allowing surface liquid water assuming a suitable atmosphere. These have been studied with global mean one-dimensional (1D) models which have defined the ‘classical habitable zone’, the range of orbital distances within which worlds can maintain liquid water on their surfaces (Kasting et al. 1993). A new generation of 3D climate models based on universal equations and tested on bodies in the solar system are now available to explore with accuracy climate regimes that could locally allow liquid water. The second key issue is now to better understand the processes which control the composition and the evolution of the atmospheres of exoplanets, and in particular the geophysical feedbacks that seem to be necessary to maintain a continuously habitable climate. From that point of view, it is not impossible that the Earth's case may be special and uncommon.

Hide All
Batalha, N.M. et al. (2011). Kepler's first rocky planet: Kepler-10b. Astrophys. J. 729, 27.
Beaulieu, J.-P. et al. (2006). Discovery of a cool planet of 5.5 Earth masses through gravitational microlensing. Nature 439, 437440.
Bonfils, X. et al. (2013). The HARPS search for southern extra-solar planets XXXI. The M-dwarf sample. Astron. Astrophys. 549, A109.
Borucki, W.J. et al. (2011). Characteristics of planetary candidates observed by Kepler. II. Analysis of the first four months of data. Astrophys. J. 736, 19.
Borucki, W.J. et al. (2012). Kepler-22b: a 2.4 Earth-radius planet in the habitable zone of a Sun-like star. Astrophys. J. 745, 120.
Brack, A. (1993). Liquid water and the origin of life. Orig. Life 3–10, 23.
Buccino, A.P., Lemarchand, G.A. & Mauas, P.J.D. (2007). UV habitable zones around M stars. Icarus 192, 582587.
Carter, B. (2008). Five- or six-step scenario for evolution? Int. J. Astrobiol. 7, 177182.
Cassan, A. et al. (2012). One or more bound planets per Milky Way star from microlensing observations. Nature 481, 167169.
Cernicharo, J. & Crovisier, J. (2005). Water in space: the water world of ISO. Space Sci. Rev. 119, 2969.
Charbonneau, D. et al. (2009). A super-Earth transiting a nearby low-mass star. Nature 462, 891894.
Ehrenfreund, P., Spaans, M. & Holm, N.G. (2011). The evolution of organic matter in space. Philos. Trans. R. Soc. Lond. A 369, 538554.
Forget, F. & Pierrehumbert, R.T. (1997). Warming early Mars with carbon dioxide clouds that scatter infrared radiation. Science 278, 12731276.
Forget, F., Hourdin, F., Fournier, R., Hourdin, C., Talagrand, O., Collins, M., Lewis, S.R., Read, P.L. & Huot, J.-P. (1999). Improved general circulation models of the Martian atmosphere from the surface to above 80 km. J. Geophys. Res. 104, 24,15524,176.
Fressin, F., Torres, G., Charbonneau, D., Bryson, S.T., Christiansen, J., Dressing, C.D., Jenkins, J.M., Walkowicz, L.M. & Batalha, N.M. (2013). The false positive rate of Kepler and the occurrence of planets. Astrophys. J. 766, 81.
Gerard, J.-C., Hauglustaine, D.A. & Francois, L.M. (1992). The faint young sun climatic paradox: a simulation with an interactive seasonal climate-sea ice model. Paleogeogr. Paleoclimatol. Paleoecol. 97, 133150.
Henning, T. & Salama, F. (1998). Carbon in the Universe. Science 282, 22042206.
Hoffman, P.F., Kaufman, A.J., Halverson, G.P. & Schrag, D.P. (1998). A neoproterozoic snowball Earth. Science 281, 13421346.
Hourdin, F., Le Van, P., Forget, F. & Talagrand, O. (1993). Meteorological variability and the annual surface pressure cycle on Mars. J. Atmos. Sci. 50, 36253640.
Hourdin, F., Talagrand, O., Sadourny, R., Regis, C., Gautier, D. & McKay, C.P. (1995). General circulation of the atmosphere of Titan. Icarus 117, 358374.
Howard, A.W., Marcy, G.W., Johnson, J.A., Fischer, D.A., Wright, J.T., Isaacson, H., Valenti, J.A., Anderson, J., Lin, D.N.C. & Ida, S. (2010). The occurrence and mass distribution of close-in super-Earths, Neptunes, and Jupiters. Science 330, 653655.
Joshi, M. (2003). Climate model studies of synchronously rotating planets. Astrobiology 3, 415427.
Kaltenegger, L., Traub, W.A. & Jucks, K.W. (2007). Spectral evolution of an earth-like planet. Astrophys. J. 658, 598616.
Kaltenegger, L., Segura, A. & Mohanty, S. (2011). Model spectra of the first potentially habitable super-Earth Gl581d. Astrophys. J. 733, 35.
Kaltenegger, L. & Selsis, F. (2007). Biomarkers set in context, in Extrasolar Planets. Dvorak, R. (ed), pp. 7598. Wiley-VCH, Berlin.
Kasting, J.F. (1988). Runaway and moist greenhouse atmosphere and the evolution of Earth and Venus. Icarus 74, 472494.
Kasting, J.F. (1997). Warming early Earth and Mars. Science 276, 12131215.
Kasting, J.F., Whitmire, D.P. & Reynolds, R.T. (1993). Habitable zones around main sequence stars. Icarus 101, 108128.
Kasting, J.F. (2001). Essay Review: P. Ward and D. Brownlee's “Rare Earth”. Perspective in biology and Medecine 44, 117131.
Korenaga, J. (2010). On the likelihood of plate tectonics on super-Earths: does size matter? Astrophys. J. 725, L43L46.
Lammer, H. et al. (2009). What makes a planet habitable? Astron. Astrophys. Rev. 17, 181249.
Lammer, H., Kislyakova, K.G., Odert, P., Leitzinger, M., Schwarz, R., Pilat-Lohinger, E., Kulikov, Y.N., Khodachenko, M.L., Güudel, M. & Hanslmeier, A. (2011). Pathways to earth-like atmospheres. Extreme ultraviolet (EUV)-powered escape of hydrogen-rich protoatmospheres. Orig. Life Evol. Biosph. 41, 503522.
Lebonnois, S., Hourdin, F., Eymet, V., Crespin, A., Fournier, R. & Forget, F. (2010). Superrotation of Venus’ atmosphere analyzed with a full general circulation model. J. Geophys. Res. (Planets) 115(E14), E06006.
Lebonnois, S., Burgalat, J., Rannou, P. & Charnay, B. (2012). Titan global climate model: a new 3-dimensional version of the IPSL Titan GCM. Icarus 218, 707722.
Leconte, J., Forget, F., Charnay, B., Wordsworth, R., Selsis, F. & Millour, E. (2013). 3D climate modeling of close-in land planets: circulation patterns, climate moist bistability and habitability. Astron. Astrophys., in press. ArXiv e-prints arXiv:1303.7079.
Léger, A. et al. (2009). Transiting exoplanets from the CoRoT space mission. VIII. CoRoT-7b: the first super-Earth with measured radius. Astron. Astrophys. 506, 287302.
Lenardic, A. & Crowley, J.W. (2012). On the notion of well-defined tectonic regimes for terrestrial planets in this solar system and others. Astrophys. J. 755, 132.
Lichtenegger, H.I.M., Lammer, H., Griemeier, J.-M., Kulikov, Y.N., von Paris, P., Hausleitner, W., Krauss, S. & Rauer, H. (2010). Aeronomical evidence for higher CO2 levels during Earth Hadean epoch. Icarus 210, 17.
Lissauer, J.J. et al. (2011). A closely packed system of low-mass, low-density planets transiting Kepler-11. Nature 470, 5358.
Longdoz, B. & Francois, L.M. (1997). The faint young sun paradox: influence of the continental configuration and of the seasonal cycle on the climatic stability. Global Planet. Change 14, 97112.
Mayor, M. & Queloz, D. (2012). From 51 peg to Earth-type planets. New Astron. Rev. 56, 1924.
Mayor, M. et al. (2009). The HARPS search for southern extra-solar planets. XVIII. An Earth-mass planet in the GJ 581 planetary system. Astron. Astrophys. 507, 487–294.
McKay, C.P., Porco, C.C., Altheide, T., Davis, W.L. & Kral, T.A. (2008). The possible origin and persistence of life on enceladus and detection of biomarkers in the plume. Astrobiology 8, 909919.
Nimmo, F. & McKenzie, D. (1998). Volcanism and tectonics on Venus. Annu. Rev. Earth Planet. Sci. 26, 2353.
O'Neill, C. & Lenardic, A. (2007). Geological consequences of super-sized Earths. Geophys. Res. Lett. 34, 19204.
Pepe, F., Lovis, C., Ségransan, D., Benz, W., Bouchy, F., Dumusque, X., Mayor, M., Queloz, D., Santos, N.C. & Udry, S. (2011). The HARPS search for Earth-like planets in the habitable zone. I. Very low-mass planets around HD 20794, HD 85512, and HD 192310. Astron. Astrophys. 534, A58.
Pierrehumbert, R. & Gaidos, E. (2011). Hydrogen greenhouse planets beyond the habitable zone. Astrophys. J. Lett. 734, L13.
Rosing, M.T. (2005). Thermodynamics of life on the planetary scale. Int. J. Astrobiol. 4, 911.
Rothschild, L.J. & Mancinelli, R.L. (2001). Life in extreme environments. Nature 409, 10921101.
Sagan, C. (1996). Circumstellar habitable zones: an introduction. In Circumstellar Habitable Zones, ed. Doyle, L.R.Travis House, Menlo Park, CA, pp. 314.
Sagan, C. & Chyba, C. (1997). The early faint young Sun paradox: organic shielding of ultraviolet-labile greenhouse gases. Science 276, 12171221.
Santerne, A., Diaz, R.F., Moutou, C., Bouchy, F., Hébrard, G., Almenara, J.-M., Bonomo, A.S., Deleuil, M. & Santos, N.C. (2012). SOPHIE velocimetry of Kepler transit candidates. VII. A false-positive rate of 35% for Kepler close-in giant candidates. Astron. Astrophys. 545, A76.
Sellers, W. (1969). A climate model based on the energy balance of the Earth-atmosphere system. J. Appl. Met. 8, 392400.
Selsis, F., Kasting, J.F., Levrard, B., Paillet, J., Ribas, I. & Delfosse, X. (2007). Habitable planets around the star Gliese 581? Astron. Astrophys. 476, 13731387.
Spiegel, D.S., Menou, K. & Scharf, C.A. (2008). Habitable climates. Astrophys. J. 681, 16091623.
Stamenkovic, V., Noack, L., Breuer, D. & Spohn, T. (2012). The influence of pressure-dependent viscosity on the thermal evolution of super-earths. Astrophys. J. 748, 41.
Stein, C., Finnenkötter, A., Lowman, J.P. & Hansen, U. (2011). The pressure-weakening effect in super-Earths: consequences of a decrease in lower mantle viscosity on surface dynamics. Geophys. Res. Lett. 38, L21201, doi:10.1029/2011GL049341.
Tarter, J.C. et al. (2007). A reappraisal of the habitability of planets around M dwarf stars. Astrobiology 7, 3065.
Tian, F. (2011). The nitrogen constraint on habitability of planets around low mass M-stars. In EPSC-DPS Joint Meeting 2011, p. 380.
Tinetti, G. et al. (2012). EChO. Experimental Astronomy, p. 35.
Tuomi, M., Anglada-Escudé, G., Gerlach, E., Jones, H.R.A., Reiners, A., Rivera, E.J., Vogt, S.S. & Butler, R.P. (2013). Habitable-zone super-Earth candidate in a six-planet system around the K2.5V star HD 40307. Astron. Astrophys. 549, A48.
Udry, S. et al. (2007). The HARPS search for southern extra-solar planets. XI. Super-Earths (5 and 8 M+) in a 3-planet system. Astron. Astrophys. 469, L43.
Valencia, D. & O'Connell, R.-J. (2009). Convection scaling and subduction on Earth and super-Earths. Earth Planet. Sci. Lett. 286, 492502.
Valencia, D., O'Connell, R.J. & Sasselov, D.D. (2007). Inevitability of plate tectonics on super-Earths. Astrophys. J. 670, L45L48.
Van Heck, H.J. & Tackley, P.J. (2011). Plate tectonics on super-Earths: equally or more likely than on Earth. Earth Planet. Sci. Lett. 310, 252261.
Von Paris, P., Gebauer, S., Godolt, M., Grenfell, J.L., Hedelt, P., Kitzmann, D., Patzer, A.B.C., Rauer, H. & Stracke, B. (2010). The extrasolar planet Gliese 581d: a potentially habitable planet? Astron. Astrophys. 522, A23.
Von Paris, P., Gebauer, S., Godolt, M., Rauer, H. & Stracke, B. (2011). Atmospheric studies of habitability in the Gliese 581 system. Astron. Astrophys. 532, A58.
Walker, J.C.G., Hays, P.B. & Kasting, J.F. (1981). A negative feedback mechanism for the long term stabilization of the Earth's surface temperature. J. Geophys. Res. 86, 97769782.
Ward, P.D. & Brownlee, D. (2000). Rare Earth. Why Complex Life is Uncommon in the Universe. Copernicus Books, New York.
Williams, D.M. & Kasting, J.F. (1997). Habitable planets with high obliquities. Icarus 129, 254267.
Wordsworth, R. (2012). Transient conditions for biogenesis on low-mass exoplanets with escaping hydrogen atmospheres. Icarus 219, 267273.
Wordsworth, R., Forget, F. & Eymet, V. (2010a). Infrared collision-induced and far-line absorption in dense CO2 atmospheres. Icarus 210, 992997.
Wordsworth, R.D., Forget, F., Selsis, F., Madeleine, J.-B., Millour, E. & Eymet, V. (2010b). Is Gliese 581d habitable? Some constraints from radiative-convective climate modeling. Astron. Astrophys. 522, A22.
Wordsworth, R.D., Forget, F., Selsis, F., Millour, E., Charnay, B. & Madeleine, J.-B. (2011). Gliese 581d is the first discovered terrestrial-mass exoplanet in the habitable zone. Astrophys. J. Lett. 733, L48.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

International Journal of Astrobiology
  • ISSN: 1473-5504
  • EISSN: 1475-3006
  • URL: /core/journals/international-journal-of-astrobiology
Please enter your name
Please enter a valid email address
Who would you like to send this to? *



Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed