W. von Bloh, C. Bounama, and S. Franck

Celestial Mechanics & Dynamical Astronomy, 92(1-3), 287-300 (2005)

Potsdam Institute for Climate Impact Research (PIK), Telegrafenberg, P.O. Box 60 12 03, 14412 Potsdam, Germany.

Abstract

In this paper, we estimate the likelihood to find habitable Earth-like planets on stable orbits for the extrasolar planetary systems epsilon Eridani, 55 Cancri, 47 Ursae Majoris, and rho Coronae Borealis and provide a new tool to assess habitability of extrasolar planetary systems. For determining the habitable zone in these systems an integrated system approach is used taking into account a variety of climatological, biogeochemical, and geodynamical processes. Habitability is linked to the photosynthetic activity on the planetary surface. We find that habitability strongly depends on the age of the stellar system and the characteristics of the Earth-like planet. In particular the portion of land/ocean coverages plays an important role. In general, a high percentage of ocean area significantly increases the probability for habitability of planets on stable orbits in extrasolar planetary systems. We show that the systems epsilon Eridani and 55 Cancri are most promising to find dynamic habitable Earth-like planets, while the system rho Coronae Borealis is most unpromising.

Keywords: extrasolar planets; geodynamics; habitable zone; orbital stability; planetary climate