Is it possible to create a realistic structure of a cometary nucleus analog in the laboratory?

Planetary analogs play a key role in the study of celestial bodies by providing controlled environments to study processes, properties, and phenomena occurring on their surfaces and interiors. For comets, analogs are constructed using porous dust-ice agglomerates to replicate the primary components of cometary material, enabling investigations into sublimation veins, cavity formation, and the behavior of gas and dust under varying conditions. Laboratory research was divided into two parts. In the first part, a laboratory system was used to conduct research under high vacuum conditions. This system consists of a vacuum chamber and a rotary and turbomolecular pump. This system allowed for determining the value of the external pressure in the chamber at which the destruction of the tested sample of the cometary nucleus analog was observed. The second part presents the results of imaging a scaled-down cometary nucleus analog using computed tomography (CT) to examine its internal structure. The CT scanning process generated a three-dimensional representation of the analog, with a two-dimensional map of the X-ray attenuation coefficient distribution. Multiple attenuation measurements, processed through reconstruction algorithms, resulted in 248 virtual cross-sections, each 1.25 mm thick. The use of computed tomography also allows for the analysis of morphological changes in the structure of the cometary nucleus analog as a function of time. Analysis of these virtual cross-sections revealed cavities where sublimating gas accumulated and veins sublimation, reflecting the complex heterogeneity observed in real cometary nucleus. By measuring the volume fractions of the individual components of the analog, its density was calculated, which is comparable to the density of real comets. These findings highlight the value of laboratory based cometary analogs in improving the understanding of the physical processes driving cometary activity and evolution. • The surface and interior of a comet nucleus analog were imaged using computed tomography. • The irregular structure of the analog was confirmed, which concerns both the surface and its interior. • We confirmed the existence of gas-filled cavities and sublimation veins resembling jets. • Based on the volume fractions determined during the measurements, the density of the analog was calculated.