We combine novel laboratory experiments and exospheric modeling to reveal that “dynamic” Ly-α photolysis of Plutonian methane generates a photolytic refractory distribution on Charon that increases with latitude, consistent with poleward darkening observed in the New Horizons images. The flux ratio of the condensing methane to the interplanetary medium Ly-α photons, φ, controls the distribution and composition of Charon’s photoproducts. Mid-latitude regions are likely to host complex refractories emerging from low-φ photolysis, while high-φ photolysis at the polar zones primarily generate ethane. However, ethane being colorless does not contribute to the reddish polar hue. Solar wind radiolysis of Ly-α–cooked polar frost past spring sunrise may synthesize increasingly complex, redder refractories responsible for the unique albedo on this enigmatic moon.

中文翻译：

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卡戎耐火材料厂

我们将新的实验室实验和外逸层模型结合起来，揭示了冥王星甲烷的“动态”Ly-α光解在卡戎上产生了随纬度增加的光解耐火材料分布，这与新视野号图像中观察到的极地变暗一致。凝结的甲烷与行星际介质 Ly-α 光子的通量比 φ 控制着卡戎的光产物的分布和组成。中纬度地区可能存在低 φ 光解产生的复杂耐火材料，而极区的高 φ 光解主要产生乙烷。但是，无色的乙烷不会导致偏红色的极性色调。春季日出后 Ly-α 煮熟的极地霜的太阳风辐射分解可能合成越来越复杂，