Global Mapping of Exo-Earths

Global Mapping of Earth-like Exoplanets from Scattered Light Curves
http://arxiv.org/abs/1004.5152

Abstract wrote:

Scattered light from terrestrial exoplanets provides valuable information about the planetary surface. Applying the surface reconstruction method proposed by Fujii et al. (2010) to both diurnal and annual variations of the scattered light, we develop a reconstruction method of land distribution with both longitudinal and latitudinal resolutions. We find that one can recover a global map of an idealized Earth-like planet without clouds on a face-on circular orbit. Using the dependence of light curves on the planetary obliquity, we also show that the obliquity can be measured by adopting the chi-square minimization or the extended information criterion. We demonstrate a feasibility of our methodology by applying it to a multi-band photometry of a cloudless model Earth with future space missions such as the occulting ozone observatory (O3). We conclude that future space missions can estimate both the surface distribution and the obliquity at least for cloudless Earth-like planets within $\sim$ 5 - 10 pc.