Pluto and its largest moon Charon display a variety of surfaces, whose thermal and energetic properties are largely unknown. Previous thermal measurements of the Pluto–Charon system yield multiple solutions because most of them did not resolve Pluto from Charon. In addition, recent modelling studies suggest that the atmospheric haze of Pluto could substantially contribute to its mid-infrared emission, thus adding further degeneracy. Here we measure separate Pluto and Charon thermal light curves over 15–25.5 μm with JWST and retrieve the thermophysical and emissivity properties of the different terrains on each. We also detect and measure the thermal emission of Pluto’s haze. The observed fluxes indicate that Pluto’s haze is composed of Titan-like organic particles as well as hydrocarbon and nitrile ices and demonstrate that the haze largely controls Pluto’s atmospheric balance. As a result, Pluto’s temperatures, climate and general circulation should therefore be substantially affected by the haze across seasons.

冥王星及其最大的卫星卡戎展示了各种表面，其热和能量特性在很大程度上是未知的。以前对 Pluto-Charon 系统的热测量产生了多种解决方案，因为它们中的大多数都无法从 Charon 中解析 Pluto。此外，最近的建模研究表明，冥王星的大气雾霾可能在很大程度上促进了其中红外发射，从而进一步加剧了简并性。在这里，我们使用 JWST 测量了 15-25.5 μm 的冥王星和卡戎热光曲线，并检索了每个地形上不同地形的热物理和发射率特性。我们还检测和测量冥王星雾霾的热发射。观测到的通量表明，冥王星的雾霾由类似泰坦的有机颗粒以及碳氢化合物和丁腈冰组成，并表明雾霾在很大程度上控制了冥王星的大气平衡。因此，冥王星的温度、气候和一般环流应该会受到不同季节的雾霾的重大影响。