Geology and Photometric Variation of Solar System Bodies with Minor Atmospheres: Implications for Solid Exoplanets
Geology and Photometric Variation of Solar System Bodies with Minor Atmospheres: Implications for Solid Exoplanets
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DOI：
10.1089/ast.2014.1165
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发表时间：
2014-09-01
期刊：
影响因子：
4.2
通讯作者：
Ohtake, Makiko
中科院分区：
文献类型：
--
作者：
Fujii, Yuka;Kimura, Jun;Ohtake, Makiko
未来对系外行星进行天文调查的合理基础是我们对太阳系中的行星和卫星的最好了解。太阳系天体呈现出各种各样的表面环境，甚至包括地球以外的潜在宜居条件，因此必须知道如何从太阳系以外的角度来描述它们的特征。在这项研究中，我们概述了在局部到全球尺度上影响地表反照率的具有较小大气的主要太阳系固体(即地月、水星、伽利略卫星和火星)的地质特征，并调查了它们如何影响UV/可见光/近红外(即反射主导范围)的点源光度测量。我们基于最新的测绘产品对它们进行模拟，并在可用的情况下汇编观测到的光线曲线。我们发现，在一次自转过程中，峰谷变化幅度为5%-50%，与各种地质过程有关，包括火成岩活动引起的表面成分不均匀，与周围含能粒子的相互作用，以及颗粒物质的分布。这些过程的一些指示由时间平均光谱组合中变化的幅度和波长相关性提供。我们还通过周期图分析估计了探测它们自转速度所需的光度精度。我们的调查说明了通过未来的直接成像观测来推断固体系外行星的详细性质的现实可能性。
A reasonable basis for future astronomical investigations of exoplanets lies in our best knowledge of the planets and satellites in the Solar System. Solar System bodies exhibit a wide variety of surface environments, even including potential habitable conditions beyond Earth, and it is essential to know how they can be characterized from outside the Solar System. In this study, we provide an overview of geological features of major Solar System solid bodies with minor atmospheres (i.e., the terrestrial Moon, Mercury, the Galilean moons, and Mars) that affect surface albedo at local to global scale, and we survey how they influence point-source photometry in the UV/visible/near IR (i.e., the reflection-dominant range). We simulate them based on recent mapping products and also compile observed light curves where available. We show a 5-50% peak-to-trough variation amplitude in one spin rotation associated with various geological processes including heterogeneous surface compositions due to igneous activities, interaction with surrounding energetic particles, and distribution of grained materials. Some indications of these processes are provided by the amplitude and wavelength dependence of variation in combinations of the time-averaged spectra. We also estimate the photometric precision needed to detect their spin rotation rates through periodogram analysis. Our survey illustrates realistic possibilities for inferring the detailed properties of solid exoplanets with future direct imaging observations.