Picture of a mantle of tholins obtained after sublimation of an intermixture of 0.1% tholins and water ice particles of around 70 μm. The sublimation was performed during 12.5 h at ≈10^-5 mbar and 200−220 K in the SCITEAS simulation chamber. A: coherent porous mantle made of water-free tholins; B: bright area made of water-ice particles exposed to the surface after ejection of a cm-sized fragment of the mantle. This image was taken in situ, while the sample was sublimating inside the SCITEAS chamber.