Scientists have suspected the existence of underground caves on the Moon for decades, and the first images from NASA’s orbiting satellites, which had mapped the lunar surface before the Apollo missions, had already suggested the presence of these structures. This extraordinary discovery was illustrated in a study just published in
Nature Astronomy
and was performed by reanalyzing radar data collected by the LRO’s Mini-RF instrument in 2010. The international team, led by the University of Trento and partly funded by the Italian Space Agency, has located a cavern extending more than 200 feet from the base of a sinkhole located 230 miles northeast of the first human landing site on the Moon, in Mare TranquillitatisThe full extent of the cavern is still unknown, but it may stretch for miles beneath the lunar mare.
The cavity, which could be a lava tube, was identified thanks to the analysis of data collected by Mini-RF (Miniature Radio-Frequency), radar instrument installed on the LRO probe The images of the lunar surface produced by Mini-Rf date back to 2010 and have been analysed with innovative signal processing techniques, recently developed by the University of Trento The working group thus discovered that A portion of the radar reflections from an area of the Sea of Tranquility may be attributable to an underground cavity. Furthermore, the researchers were able to create a model representing the initial part of the duct.
“Radar measurements play a crucial role in understanding the morphology and composition of planetary surfaces and subsurfaces. – commented Alessandra Tiberia, ASI responsible for the scientific activities of the radars for the JUICE, MRO and EnVision missions – Radar data, in fact, provide information on what happens beneath the surface of planets and this information could constitute a paradigm shift in human space exploration: Lava tubes could not only provide information on the evolution of the planets themselves, but also provide a temperature-controlled environment protected from cosmic and solar radiation for possible human settlements.. In this perspective, the Italian Space Agency is actively involved in the participation in various interplanetary missions involving radar instrumentation, enhancing the potential and the valuable skills present in the Italian scientific community, of the highest level. The achievement of this important result – continues Tiberia – This was made possible thanks to the development of advanced data processing techniques, which on the one hand are essential for scientific progress and on the other are preparatory to the definition of scientific requirements for future missions.“.
Like “lava tubes” on Earth, scientists suspect that lunar caverns formed when molten lava flowed beneath a layer of cooled lava, or when a crust formed over a lava river, leaving a long, empty tunnel.
Processing of a photo by A. Romeo. NASA LRO 3D model (Credits: Brian Kumanchik, Christian Lopez, NASA, JPL/Caltech) – photo taken in 1968 by Apollo 8 astronaut Bill Anders.