We present a new search for dark matter (DM) using planetary atmospheres. We point out that annihilating DM in planets can produce ionizing radiation, which can lead to excess production of ionospheric ${\mathrm{H}}_3^{+}$. We apply this search strategy to the night side of Jupiter near the equator. The night side has zero solar irradiation, and low latitudes are sufficiently far from ionizing auroras, leading to a low-background search. We use Cassini data on ionospheric ${\mathrm{H}}_3^{+}$ emission collected three hours either side of Jovian midnight, during its flyby in 2000, and set novel constraints on the DM-nucleon scattering cross section down to about ${10}^{-38}{\mathrm{cm}}^2$. We also highlight that DM atmospheric ionization may be detected in Jovian exoplanets using future high-precision measurements of planetary spectra.

中文翻译：

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卡西尼号在木星夜间寻找暗物质电离


我们提出了利用行星大气寻找暗物质（DM）的新方法。我们指出，消灭行星中的 DM 会产生电离辐射，从而导致电离层 ${\mathrm{H}}_3^{+}$ 的过量产生。我们将这种搜索策略应用于木星赤道附近的夜间一侧。夜间的太阳辐射为零，低纬度地区距离电离极光足够远，因此需要进行低本底搜索。我们使用卡西尼号在 2000 年飞越木星期间在木星午夜两侧三小时收集的电离层 ${\mathrm{H}}_3^{+}$ 发射数据，并对 DM 核子散射截面设置新的限制，低至约 ${10}^{-38}{\mathrm{cm}}^2$ .我们还强调，通过未来对行星光谱的高精度测量，可以在木星系外行星中检测到DM大气电离。