Europa’s surface continuously experiences high fluxes of charged particles due to the presence of Jupiter’s strong magnetic field. These high-energy charged particles, including electrons, interact with the ice- and salt-rich surface, resulting in complex physical and chemical processes. Here, we report that Europa ice analogues emit characteristic spectral signatures in the visible region when exposed to high-energy electron radiation. The strongest emission (ice glow) we observed was centred at ~525 nm. We found that the presence of sodium chloride and carbonate strongly quenched, while epsomite enhanced, the radiation-induced ice glow. These emission characteristics could be used to determine the chemical composition of Europa’s surface during night-time low-altitude fly-bys of spacecraft such as the Europa Clipper. We estimate that the Europa Clipper Wide Angle Camera could record between 500 and 280,000 counts per second through different colour filters, depending on the chemical composition of Europa’s surface. Though we focus here on Europa, our study may be relevant to other bodies exposed to high doses of ionizing radiation, such as Io and Ganymede. With its extreme radiation environment, rich surface geology and compositional diversity, the radiation-induced ice glow on Europa could enable more precise surface characterization and provide unique night-time views.

由于木星的强磁场的作用，木卫二的表面连续不断地经历带电粒子的高通量。这些包括电子在内的高能带电粒子与富含冰和盐的表面相互作用，导致复杂的物理和化学过程。在这里，我们报告说，欧罗巴冰类似物在暴露于高能电子辐射时会在可见光区域发出特征性的光谱特征。我们观察到的最强发射（冰光）集中在〜525 nm。我们发现氯化钠和碳酸盐的存在强烈淬灭，而泻石增强了，辐射诱导的冰发光。这些发射特性可用于确定夜间飞船（例如“欧罗巴快船”）低空穿越时欧罗巴表面的化学成分。我们估计，根据欧罗巴表面的化学成分，欧罗巴Clipper广角相机可以通过不同的滤色器每秒记录500至280,000个计数。尽管我们将重点放在欧罗巴上，但我们的研究可能与其他暴露于高剂量电离辐射的物体有关，例如艾欧和木卫三。凭借其极端的辐射环境，丰富的地表地质和成分多样性，木卫二上的辐射诱发的冰辉可以实现更精确的表面特征并提供独特的夜间景观。例如Io和Ganymede。凭借其极端的辐射环境，丰富的地表地质和成分多样性，木卫二上的辐射诱发的冰辉可以实现更精确的表面特征并提供独特的夜间景观。例如Io和Ganymede。凭借其极端的辐射环境，丰富的地表地质和成分多样性，木卫二上的辐射诱发的冰辉可以实现更精确的表面特征并提供独特的夜间景观。