Why We Should Build a Moon Village
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MOON VILLAGE Why we should build a Moon village Ian Crawford explains how science would benefit from a human outpost on the Moon. he director general of the European kind of transportation and other infrastruc- Specific planetary science activities that Space Agency, Jan Wörner, has sug- ture required to establish a Moon village would benefit from such a lunar surface Tgested that the creation of a human– would likely facilitate human and robotic infrastructure include (see e.g. NRC 2007, robotic lunar outpost would be a logical operations at locations that may not be local Crawford & Joy 2014, Neal et al. 2014, and next step in human space exploration to the village itself. Moreover, references cited therein) (e.g. Wörner & Foing 2016). The creation in the fullness of time, just as “The lunar geological inner solar system bom- of such a Moon village (figure 1) would in Antarctica today, we might record still has much to bardment history, impact offer significant scientific opportunities by envisage multiple such out- tell us about the early cratering processes, the lunar providing an infrastructure on the lunar posts at different locations. solar system” interior including volatile surface, analogous to the way that human With these caveats in mind, content, regolith processes outposts in Antarctica (figure 2) facilitate we here address the major areas of science and serendipitous discoveries. research activities across multiple scien- that would benefit from the scientific infra- The lunar cratering rate is used to tific disciplines on that continent. In the structure represented by a Moon village. estimate the ages of cratered surfaces case of a Moon village, scientific fields that throughout the solar system, but it is not might benefit include planetary science, Planetary science well calibrated (e.g. Robbins 2014). Improv- astronomy, astrobiology, life sciences and As discussed by Crawford & Joy (2014), ing this calibration is a key objective of fundamental physics (e.g. Taylor 1985, the lunar geological record still has much planetary science, and requires sampling Ehrenfreund et al. 2012, McKay 2013, Craw- to tell us about the earliest history of the impact melt deposits from multiple (ideally ford & Joy 2014). In addition, a Moon village solar system, the origin and evolution of the hundreds) of impact craters of a wide range would help assess the economic potential Earth–Moon system, the geological evolu- of ages. In addition, recovering fragments of lunar resources, while also acting as a tion of rocky planets, and the near-Earth of the impacting bodies would reveal how market for them (e.g. Crawford 2015). cosmic environment throughout solar sys- and if the population of impactors has The extent to which different scientific tem history. Having humans operating on changed with time (Joy et al. 2012, 2016). fields would benefit from a lunar outpost the lunar surface would enable much better Accessing these materials requires a signifi- would, in part, depend on its location and access to this record, especially if supported cant transportation infrastructure (such as on the length of time for which it is occu- by a scientific infrastructure such as that pressurized rovers; figure 3) on the lunar pied. Some of the scientific areas discussed envisaged for the Moon village. A much surface, a significant sample return capacity below are more dependent on these factors wider range of rock and soil samples could and, ideally, in situ analytical instruments. than others. For example, science questions be collected, analysed (and, if necessary, Impact cratering is a fundamental plan- related to the lunar poles would clearly shipped to Earth), and the base would sup- etary process, but our understanding of it is benefit more from a polar Moon village port implementation of complex explora- limited by lack of access to pristine craters than an equatorial one. Nevertheless, the tory activities such as subsurface drilling. of a wide range of sizes. The lunar surface 6.18 A&G • December 2017 • Vol. 58 • aandg.org MOON VILLAGE 1 (Left) Artist’s impression of a Moon village. (ESA) facilitated by a human and 2 (Below) The Amundsen–Scott research station at Earth’s South Pole. robotic infrastructure on the Such outposts provide a scientific infrastructure that supports research Moon. Key aspects include in multiple disciplines (e.g. astronomy, atmospheric science, biology, low-frequency radio astron- glaciology, geology, magnetospheric physics, meteoritics and zoology) on omy, optical and infrared the Antarctic continent that would be difficult or impossible to sustain astronomy, high-energy otherwise. Lunar research stations will fulfil the same function astrophysics and funda- on the Moon. (NSF) mental physics. 3 (Right) The Lunar Electric Rover, under development by Radio wavelengths NASA. Many lunar science activities will require the ability to longer than about 10 m move away from the outpost, requiring pressurized rovers, cannot penetrate the but conversely a lunar outpost will provide the facilities to Earth’s ionosphere, yet maintain, recharge and upgrade such vehicles. (NASA) much valuable scientific information is expected to lie in this low-frequency range (e.g. Jester & Falcke 2009). The lunar farside, which is permanently shielded from the Earth, is probably the best location in the inner solar system for such observations and a human infrastructure on the Moon would assist in the setting up of the neces- sary equipment (although care would also be required to ensure that human opera- tions do not degrade the natural radio- quietness of the location). Although the Moon could in principle provide a platform for optical and infrared telescopes, there is a consensus that free- flying satellites (e.g. at the Earth–Sun L2 point) probably provide better platforms for such activities (Lester et al. 2004). It is certainly true that some aspects of the lunar surface environment (e.g. dust and, in most locations, extreme diurnal temperature clearly exhibits the required diversity of meteorites have played in delivering vola- ranges) are not ideal for astronomical obser- craters. Using these craters to improve our tile substances to the terrestrial planets. vations at these wavelengths. Nevertheless, knowledge of impact cratering processes Determining the nature and extent of these access to a scientific infrastructure able requires visiting many craters of a wide volatiles requires surface activities (includ- to emplace, maintain and upgrade such range of sizes and ages to conduct sam- ing sampling and near-surface drilling) at instruments (the value of which has been pling, geophysical surveys and, possibly, polar and high-latitude locations. demonstrated by multiple HST servicing subsurface drilling. The lunar surface is a natural labora- missions) might compensate for these dis- The Moon provides an excellent example tory for understanding space weathering advantages. Moreover, the stability of the of a small rocky body that largely preserves and regolith processes throughout the lunar surface may be enabling in the con- its internal structure from solar system, through time. text of building optical/IR interferometric shortly after its formation. As “The Moon could be Access to regoliths of differ- arrays, and permanently shadowed polar such it can provide insights a useful platform ent composition, thickness craters might enable passive cooling of IR into the early geological for astronomical and latitude are required to instruments. The pros and cons of the lunar evolution of larger and more observations” improve our knowledge of surface for optical/IR astronomy still need complicated planets. To bet- these processes. to be properly assessed and a lunar outpost ter understand the structure, composition Humans are unique in our ability to would at least facilitate such an assessment. and evolution of the lunar interior requires recognize the significance of new observa- As the lunar surface is not shielded by emplacement of geophysical tools (e.g. tions or phen om ena, even if they were not either an atmosphere or a magnetic field seismic networks and magnetic surveys), anticipated. Having humans living and (other than the Sun’s heliospheric mag- as well as sampling a wide range of lunar working on the lunar surface for long peri- netic field) it is an attractive location from crustal and volcanic rocks of diverse ages ods is likely to result in unanticipated dis- which to study the flux and composition and compositions. Such studies would also coveries that might not otherwise be made. of primary cosmic rays. This can also be help constrain theories of lunar origin. Although unquantifiable, such discoveries done in free space, but the existence of a There is now convincing evidence may ultimately prove to be among the most human and robotic infrastructure on the that water ice exists within permanently significant to result from a lunar outpost. lunar surface may facilitate the installation shadowed polar craters, and that hydrated of the required instrumentation. Similar materials also exist at high-latitude (but Astronomy arguments apply for gamma-ray and X-ray not permanently shadowed) localities (see The lunar surface is a potentially useful observations. Anand 2010 for a review). In addition to platform for astronomical observations Although not a major driver for lunar their possible value as resources (dis- (e.g. Burns et al. 1990, Crawford & Zarnecki exploration, several areas of fundamental cussed below), such deposits would inform 2008), and establishing the equipment physics research may benefit from the sci- our knowledge of the role comets and required for such observations would be entific infrastructure represented by a lunar A&G • December 2017 • Vol. 58 • aandg.org 6.19 MOON VILLAGE 4 Several lunar science objectives require accessing the subsurface and may require drilling to depths of tens or hundreds of metres (e.g. Crawford et al. 2010). A lunar outpost would provide the background supporting infrastructure required to enable such activities, just as Antarctic research stations are required to support scientific drilling on that continent.