Extrasolar Planets

Earth-like Habitats in Planetary Systems

By Keith Cowing
April 18, 2014
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Earth-like Habitats in Planetary Systems

Understanding the concept of habitability is related to an evolutionary knowledge of the particular planet-in-question. Additional indications so-called “systemic aspects” of the planetary system as a whole governs a particular planet’s claim on habitability.

Here we focus on such systemic aspects and discuss their relevance to the formation of an ‘Earth-like’ habitable planet. We summarize our results obtained by lunar sample work and numerical models within the framework of the Research Alliance “Planetary Evolution and Life”. We consider various scenarios which simulate the dynamical evolution of the Solar System and discuss the likelihood of forming an Earth-like world orbiting another star. Our model approach is constrained by observations of the modern Solar System and the knowledge of its history. Results suggest that the long-term presence of terrestrial planets is jeopardized due to gravitational interactions if giant planets are present. But habitability of inner rocky planets may be supported in those planetary systems hosting giant planets.

Gravitational interactions within a complex multiple-body structure including giant planets may supply terrestrial planets with materials which formed in the colder region of the proto-planetary disk. During these processes, water, the prime requisite for habitability, is delivered to the inner system. This may occur either during the main accretion phase of terrestrial planets or via impacts during a post-accretion bombardment. Results for both processes are summarized and discussed with reference to the lunar crater record.

Starting from a scenario involving migration of the giant planets this contribution discusses the delivery of water to Earth, the modification of atmospheres by impacts in a planetary system context and the likelihood of the existence of extrasolar Earth-like habitable worlds.

Jörg Fritz, Bertram Bitsch, Ekkehard Kührt, Alessandro Morbidelli, Carmen Tornow, Kai Wünnemann, Vera A. Fernandes, Lee J. Grenfell, Heike Rauer, Roland Wagner, Stephanie C. Werner (Submitted on 17 Apr 2014)

Comments: 36 Pages, 6 figures, 2014, Special Issue in Planetary and Space Science on the Helmholtz Research Alliance on Planetary Evolution and Life

Subjects: Earth and Planetary Astrophysics (astro-ph.EP) DOI: 10.1016/j.pss.2014.03.003

Cite as: arXiv:1404.4460 [astro-ph.EP]  (or arXiv:1404.4460v1 [astro-ph.EP] for this version)

Submission history From: Joerg Fritz [v1] Thu, 17 Apr 2014 09:31:45 GMT (659kb)

SpaceRef co-founder, Explorers Club Fellow, ex-NASA, Away Teams, Journalist, Space & Astrobiology, Lapsed climber.