An analysis of radiation safety issues on lunar lava tubes as potential manned habitats has been performed. Lava tubes are formed when an active low-viscosity lava flow develops a continuous and hard crust, which thickens and forms a roof above the still flowing lava stream. At the end of the extrusion period, an empty flow channel free from molten magma is left. Lava tubes are commonly observed on the Earth, on basaltic volcanic terrains, with typical sizes of the order of 1-2 km of length, and few meters for cross-sectional parameters (i.e. height and width). Under lunar conditions (i.e. lower gravity field, absence of atmosphere), lava channels and tubes are at least an order of magnitude larger in each size dimension, i.e. hundreds of meters wide by hundred of meters or more deep, and tenths of kilometers long. For many years it has been suggested that these natural cavities on the Moon could provide an ideal location for a manned lunar base, by providing shelter from various natural hazards, such as cosmic rays radiation, meteorites, micrometeoroids, and impact crater ejecta, and also providing a natural environmental control, with a nearly constant temperature, unlike that of the lunar surface showing extreme variation in its diurnal cycle. The analysis has been performed considering radiation from galactic cosmic rays (GCR) and Solar Particle Events (SPE) interacting with the lunar surface, modeled as a regolith layer and rock. The chemical composition has been chosen as typical of the lunar regions where the largest number of lava tube candidates are found. Particles have been transported all through the regolith and the rock, and received particles flux and doses have been calculated. The radiation safety of lunar lava tubes environments has been demonstrated.
AAS/Division for Planetary Sciences Meeting Abstracts #33
- Pub Date:
- November 2001