Predicting Sky Dome Appearance on Earth-like Extrasolar Worlds

Abstract

In this paper, we present a case study on how, given some reasonable assumptions, a sky dome model originally developed for terrestrial Predictive Rendering purposes can be re-used to give a scientifically plausible first impression of what outdoor scenes on earth-like exoplanets with a similar atmospheric structure would look like. On this very specific type of exoplanet, humans could reasonably be expected to survive without a space suit, and life-forms very similar to those found on Earth could theoretically evolve. This makes a simulation of typical outdoor lighting on this kind of planet interesting for various scientific (speculative exo-biological simulations) and not so scientific ("realistic" science fiction movie settings) reasons. If the properties of the exoplanet itself are restricted to resemble Earth, the remaining free parameter are the sun(s) which the exoplanet orbits. In the course of our case study, we found that even for fairly different star types, the overall appearance of the sky does not change as much as one might assume at first. Also, even the skies of Earth-like worlds that orbit binary stars would have a fairly normal appearance, although specific oddities can be observed.