Aiming at obtaining detailed information of surface environment of Earth
analogs, Kawahara & Fujii (2011) proposed an inversion technique of annual
scattered light curves named the spin-orbit tomography (SOT), which enables one
to sketch a two-dimensional albedo map from annual variation of the
disk-integrated scattered light, and demonstrated the method with a planet in a
face-on orbit. We extend it to be applicable to general geometric
configurations, including low-obliquity planets like the Earth in inclined
orbits. We simulate light curves of the Earth in an inclined orbit in three
photometric bands (0.4-0.5um, 0.6-0.7um, and 0.8-0.9um) and show that the
distribution of clouds, snow, and continents is retrieved with the aid of the
SOT. We also demonstrate the SOT by applying it to an upright Earth, a tidally
locked Earth, and Earth analogs with ancient continental configurations. The
inversion is model independent in the sense that we do not assume specific
albedo models when mapping the surface, and hence applicable in principle to
any kind of inhomogeneity. This method can potentially serve as a unique tool
to investigate the exohabitats/exoclimes of Earth analogs.Comment: 15 pages, 14 figures, 2 tables; published in The Astrophysical
Journa