Scientific exploration of lava tubes and pits in the solar system, takeaways from the DaedalusCAM concept

• Introduction

Lava tubes and impact melt pits, in planetary settings have gained increasing attention during the last years. They have many characteristics that made them suitable locations for the future development of settlements on the Moon or Mars [1]. These systems can be associated with large underground spaces, which present several advantages in comparison to locations exposed to the surface, like protection from radiation and extreme environmental conditions, stable temperatures, solid terrain, and even the possibility of hosting water and other volatiles [2,3].

Unfortunately, accessibility to the caves is difficult, as the only entrances are usually collapsed portions of the roof, which end up creating vertical holes that are difficult to traverse and explore [4]. Within this context, the DaedalusCAM is a protype system thought to explore the collapses leading to lava tube or underground caves, by using a novel hyper-hemispheric camera able to gather information in 360 degrees [5]. After three years of testing the camera in the laboratory and in analogue environments on Earth, some conclusions can be drawn about the effectiveness of the system to deliver geological results, and its implications for planetary exploration.  

• Data and Methods

In order to evaluate the scientific viability of DaedalusCAM in an extraterrestrial environment, we designed test scenarios in lava tubes in Mount Etna in Italy, and in Lanzarote in Spain. They consisted in comparing geological features measured in the images and 3D models from DaedalusCAM and those from traditional exploration systems like laser scanners and geological field measurements.

Two types of datasets were tested, optical panoramic images deconvolved from DaedalusCAM and from a BLK360 laser scanner, and 3D models reconstructed from the same images using photogrammetry and LiDAR points. All the measurements in the 3D outcrop models were carried out in the VRGS and QGIS software. Finally, hand-made measurements along scanlines and stratigraphic sections were collected to serve as a ground control (Figure 1).

Figure 1: Methodology to evaluate the accuracy of DaedalusCAM.

• Results and discussion

The field campaigns to collect the datasets took place on Mount Etna and Lanzarote, both locations host lava tubes with collapsed roofs, analogue to the lunar and martian scenarios, although smaller in size. The hand-made measurements consisted of collecting attitude and thickness of lava layers along stratigraphic section, and fracture orientations and density along scanlines. Although direct measurements on rocky outcrop theoretically retrieve the most reliable results, this does not seem to be the case in locations dominated by lava flow fields. They usually have low slopes and locally changing values of strike and dip, because they are mostly controlled by the paleotopography. This makes uncertain the identification of dominant trends, especially in unpractical locations like lava tube collapses. This problem also arises when studying fractures, as they are caused by planar isotropic thermal fracturing.

The digital models obtained with the laser scanner overcome these challenges not only by allowing the measurement of unreachable layers near to the top of the collapses, but also because they permit a quick visualization of the layers at a larger scale, resulting in a more accurate interpretation of their average attitude (Figure 2).

Figure 2: Structural measurements on the 3D model from the laser scanner to the left, a pole density and a rose diagram of the stratification to the right.

The DaedalusCAM images were collected along a transect inside the cave and another one outside it. We found two important factors affecting the results of the panoramic camera:  i) proximity to the outcrop, being acquisition distances closer to 5 meters more effective; and ii) illumination conditions, since a diffuse light allow a better resolution while avoiding the saturation and sharp shadows that direct sunlight generates. In the best conditions, the images of DaedalusCAM have enough detail to identify fractures, stratification, and the diverse facies of the lava flows, although the results are not homogeneous across the image. The resolution of the laser scanner was better, especially at distance, allowing the recognition of the same parameters in smaller features. Nevertheless, the large spatial coverage of DaedalusCAM also make it a useful tool for terrain traversing and spatial awareness, since one lense can capture half of a scene, it can provide more information in real time than any other single optical instrument. 

• Conclusions

DaedalusCAM is a versatile system that can be applied not only on robotic system aimed at the exploration of lava tube collapses, but also in other scenarios such as mounted on hoppers, rovers, and even on astronaut suits. Besides, the generation of 3D outcrop models by photogrammetry is particularly useful for mobility and real time spatial awareness. Major challenges remain in traversing difficult terrains and dealing with sharp contrasts in illumination, but DaedalusCAM is likely a part of the solution, one that can be worked upon and integrated in other systems.   

References

Carrer, L., Pozzobon, R., Sauro, F., Castelletti, D., Patterson, G. W., & Bruzzone, L. (2024). Radar evidence of an accessible cave conduit on the Moon below the Mare Tranquillitatis pit. Nature Astronomy, 8(9), 1119-1126. https://doi.org/10.1038/s41550-024-02302-y

Romio, F. A. P., Lobosco, G., Sauro, F., Pozzobon, R., & Marraffa, A. (2025). Pyroduct: A novel parametric software for the simulation of terrestrial, lunar, and Martian lava tubes. Icarus, 447, 116904. https://doi.org/10.1016/j.icarus.2025.116904

She, X., Wang, J., Xu, W., & Xiao, L. (2024). Research on the impact of extraterrestrial lava tube environments on human survival and countermeasures. Space Habitation., 1(1), 100002. https://doi.org/10.1016/j.spaceh.2024.100002

Wilcoski, A. X., Hayne, P. O., & Elder, C. M. (2023). Thermal Environments and Volatile Stability Within Lunar Pits and Caves. Journal Of Geophysical Research Planets, 128(7). https://doi.org/10.1029/2023je007758

Simioni, C. Pernechele, R. Pozzobon, M. Massironi, V. Della Corte, M. Lan-doni, B. Saggin, and D. Scaccabarozzi, (2023). “The Daedalus CAM: The immersive and stereoscopic way for lunar lava tubes exploration”, Internationa Planetary Caves Coference 2023.