full title, "Thorium Abundances in Solar Twins and Analogues: Implications for the Habitability of Extrasolar Planetary Systems".
Posted on 05/11/2015 11:50:43 AM PDT by SunkenCiv
We present the first investigation of Th abundances in Solar twins and analogues to understand the possible range of this radioactive element and its effect on rocky planet interior dynamics and potential habitability.
The abundances of the radioactive elements Th and U are key components of a planet's energy budget, making up 30% to 50% of the Earth's (Korenaga 2008; Allegre et al. 2001; Schubert et al. 1980; Lyubetskaya & Korenaga 2007; The KamLAND Collaboration 2011; Huang et al. 2013). Radiogenic heat drives interior mantle convection and surface plate tectonics, which sustains a deep carbon and water cycle and thereby aides in creating Earth's habitable surface. Unlike other heat sources that are dependent on the planet's specific formation history, the radiogenic heat budget is directly related to the mantle concentration of these nuclides.
As a refractory element, the stellar abundance of Th is faithfully reflected in the terrestrial planet's concentration. We find that log eps Th varies from 59% to 251% that of Solar, suggesting extrasolar planetary systems may possess a greater energy budget with which to support surface to interior dynamics and thus increase their likelihood to be habitable compared to our Solar System.
(Excerpt) Read more at astrobiology.com ...
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Yet another in a long list of design criteria for an Earthlike planet. Like Ward & Brownlee said in their book, Rare Earth, it’s very hard to find a planet near enough like Earth for advanced like. Maybe even only ONE in a galaxy. Yes, we are alone. Well, except for the Creator and what He’s made.
Yet another claim that the book “Rare Earth” was at all scientific.
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