Doles 3 estimations of the HZ have been based on an optical thin atmosphere and

Doles 3 estimations of the hz have been based on an

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Dole‘s [3] estimations of the HZ have been based on an optical thin atmosphere and a fixed albedo model. He finds 0.725 AU for the inner boundary and 1.24 AU for the outer boundary of the HZ, respectively. Hart [9, 10] calculated the hypothetical evolu- tion of the terrestrial atmosphere over geologic time for different orbital radii. He found that the HZ, i.e. the “ecological niche” between runaway greenhouse and run- away glaciation processes is amazingly narrow for stars like our Sun: It is delimited from below by R inner = 0.958 AU and from above by R outer = 1.004 AU, where R inner r and R outer are the inner and outer limits to the mean orbital radius, respectively. A main disadvantage of those calculations was the neglect of the negative feedback between atmospheric CO 2 partial pressure and mean global surface temperature via the carbonate-silicate cycle as discovered by Walker et al. [11]. The inclusion of that feed- back by Kasting et al. [12] produced the interesting result of an almost constant inner
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