When Neil Armstrong first stepped on the Moon, from Apollo 11’s lunar module, on July 20, 1969, his iconic words -- “That’s one small step for a man, one giant leap for mankind” -- were more than a catchphrase for posterity. They reflected the futuristic fascination that drew the human species to the Moon and beyond, for adventure, science, exploration, and at present hypothetically speaking, ‘colonisation’.
The Moon, being the Earth’s nearest celestial object, has particularly evoked immense interest for its sheer majesty, and also as a gateway to further future cosmic odysseys. Accordingly, astrophysicists and the pundits of sci-fi have charted a theoretical roadmap for colonisation of the Moon. The idea is that in the future, humans may live and work on the moon for weeks or even months.
It is a process or concept employed by some proposals for robotic or human exploitation and settlement endeavours on Earth’s natural satellite. Energy and power will make it possible to travel to and live on the lunar surface. Humans must choose the appropriate energy source and technological means to produce that power. Solar energy is abundant on the moon, and ways must be found to effectively harness it.
While a range of proposals for missions of lunar colonisation, exploitation or permanent exploration have been raised, current projects for establishing a permanent crewed presence on the Moon are not for colonisation, but to focus on building moonbases for exploration and to a lesser extent for harnessing lunar resources. In reality, currently, global space agencies, including India’s ISRO, are looking at studying specific regions of the lunar surface, to understand the scientific potential that the Moon may unlock, as we dive deeper into space.
When we talk about looking at a suitable perennial energy resource to run extended lunar missions, in the form of crewed stations, one must also take into account the topography and environment of the Moon. The Moon is not one smooth white/grey ball of rock. Its surface is composed of Anorthosite, which is a calcium-rich white rock, almost entirely made up of plagioclase feldspar, a common, light-weight, light-coloured mineral on Earth. It is an igneous rock, which means it cooled and solidified from hot melted material.
Also, the Moon’s environment is not nearly as easy to live in as Earth’s. Apart from the toxic lunar dust, the sparse atmosphere provides no protection from meteorites or radiation. The temperature fluctuations on the Moon are also intense, ranging from -248 to 127 degrees Celsius. This again leads to the question of how can the Moon be made more survivable, begging the need for shelters. In addition to protecting inhabitants from meteorites, radiation and toxic lunar dust, a sealed shelter would allow them to breathe. While the pursued purpose of moonbases is mostly for space exploration, exploiting and commercialising the Moon, it also theoretically advocates for a lunar and cis-lunar infrastructure, economy and settled society. Hence, conditions ought to be appropriated.
Discovery of a cave
In this direction, just this week, a team of international scientists, under the lead of the University of Trento, Italy, have made a breakthrough. They published a paper in Nature Astronomy, demonstrating the existence of a tunnel in the lunar subsurface. It seems to be an empty lava tube, which could pave the way for human habitation on the Moon. “These caves have been theorised for over 50 years, but it is the first time ever that we have demonstrated their existence,” explains Lorenzo Bruzzone, professor at the University of Trento.
How was this demonstration achieved? Bruzzone explains: “In 2010, as part of the ongoing LRO NASA mission, the Miniature Radio-Frequency (Mini-RF) instrument acquired data that included a pit in Mare Tranquilitatis. Years later we have reanalysed this data with complex signal processing techniques we have recently developed, and have discovered radar reflections from the area of the pit that are best explained by an underground cave conduit. This discovery provides the first direct evidence of an accessible lava tube under the surface of the Moon.”
“Thanks to the analysis of the data we were able to create a model of a portion of the conduit,” continues Leonardo Carrer, researcher at University of Trento. This study has scientific implications for the development of missions to the Moon, where the environment is hostile to human life. The aforesaid conditions drive the need to find safe sites for the construction of infrastructure that can support sustained exploration. Caves such as this one offer a solution to that problem, the scientists conclude. Breathing on the Moon is out of question.
The Moon technically does have an atmosphere, but the gases are so spread out that they do not support breathing. Experiments on the International Space Station have shown how recycling air systems could be adapted for the Moon. This could look like planting oxygen-emitting plants in lunar greenhouses, and then sending the purified air through sealed habitation pods.
First lunar station
The future is now. NASA and its partners are already developing the foundational systems needed for long-term exploration of the Moon, with the Artemis campaign. “Following the Artemis III mission that will land the first people near the Moon’s South Pole, astronauts on Artemis IV will live and work in humanity’s first lunar space station, Gateway, which will enable new opportunities for science and preparation for human missions to Mars. The mission will bring together an intricate choreography of multiple launches and spacecraft dockings in lunar orbit, and will feature the debut of NASA’s larger, more powerful version of its SLS (Space Launch System) rocket and new mobile launcher,” says NASA.
The Moon is even closer to the Earth today, than it is. It is technically possible to live on it, say scientists, but many small steps for science and sustainability are needed, before that leap.