Planetary Caves: A Solar System View of Processes and Products

Abstract

In 1966, while examining some of the earliest images of the lunar surface, researchers identified several dark features, which were postulated to be cave entrances (Heacock et al., 1966). Later that year, Halliday (1966) further mused over the existence of lunar caves and briefly discussed their potential importance for future human

Potential Caves: Inventory of Subsurface Access Points on the Surface of Titan

“…On many bodies of interest in our solar system, caves and/or the deep subsurface represents a sequestered environment that is safe from ionizing radiation, thermally buffered, devoid of light, with physical properties that may allow different deposits to seep out of the walls (Wynne, Mylroie, et al., 2022; Wynne, Titus, et al., 2022). For many bodies with harsh conditions, the subsurface can provide a potential astrobiological refuge prime for investigation (Titus et al., 2021; Wynne, Mylroie, et al., 2022). However, on Titan, the subsurface does not present a unique thermal or radiation‐buffered environment relative to the open surface.…”

“…For Titan, subsurface access points, or SAPs (we use this term in lieu of "cave entrance" as the latter presupposes a cave actually exists), represent potential entrances to the subsurface that permit surface organics to be transported deeper into the interior, whether as solution or as suspended insoluble materials. For the purposes of our discussion, we are using the concept of subsurface access points (SAPs) provided by Wynne, Mylroie, et al (2022) to imply remotely sensed features, that may or may not be connected to a subsurface void or cave, and thus potentially provide access to the subsurface of a planetary body. However, dissolution and transport of fluids to the subsurface occurs at a much smaller scale than what can be resolved via current remote sensing capabilities.…”

Fundamental Science and Engineering Questions in Planetary Cave Exploration

“…Technical hurdles for a robotic cave exploration mission are indeed significant. However, robots represent the best chance for humans to examine a lunar and/or Martian cave within the next one to two decades (Titus et al, 2021;Wynne et al, 2022). To make robotic exploration of a planetary cave possible, critical…”

“…For example, on Enceladus, within the four primary fractures of the south polar region, at least 100 active geysers have been identified (Porco et al., 2014 ). Incidentally, steep‐sided depressions and equatorial pits have been observed on Titan (Wynne et al., 2022 ), which may have resulted from hydrocarbon fluids percolating through thick organic materials in a process similar to karstic dissolution (Malaska et al., 2020 ). Thus far, 3,545 SAPs have been identified on 11 bodies across our solar system (Wynne et al., 2022 ).…”

“…Incidentally, steep‐sided depressions and equatorial pits have been observed on Titan (Wynne et al., 2022 ), which may have resulted from hydrocarbon fluids percolating through thick organic materials in a process similar to karstic dissolution (Malaska et al., 2020 ). Thus far, 3,545 SAPs have been identified on 11 bodies across our solar system (Wynne et al., 2022 ). Additionally, possible volcanic vents have been observed on Triton and Pluto, and numerous pit crater chains on icy and rocky bodies will require further examination (Wynne et al., 2022 ).…”