Free Astronomy Magazine July-August 2018

JULY-AUGUST 2018 the surfaces, useful for identifying possible landing sites. The close approach will be es- sential even to know the consistency of the regolith and the debris covering those sur- faces, a feature almost impossible to de- scribe today through remote observation. In this regard, the case of the Eros and Itokawa asteroids is emblematic: both are very simi- lar in terms of spectrum and reflectivity when viewed from Earth, but they revealed very different surface materials when visited by NEAR Shoemaker and Hayabusa probes. Eros is covered with fine regolith, while rub- ble of a few centimeters in size is prevalent on the surface of Itokawa. In both cases, however, we do not know how deep these surface materials extend. Without adequate knowledge of the prop- erties and distribution of surface material, it is impossible to develop a strategy for landing and extracting resources. Because of the feeble gravity of NEAs, any activity practiced on them may have unpredictable effects even in the absence of information on the innermost structure of those aster- oids: the presence of empty spaces or mate- rial not sufficiently sturdy to support mining operations can put mining activity at risk. also able to quickly alert seekers upon dis- covery. Asteroid Mining Corporation (Tar- leton, Preston, UK), is also planning a small space telescope specifically designed for re- search and the spectroscopic study of NEAs, which should be launched into low-Earth orbit by 2020. Whatever method of investigation is adopted, spectroscopic studies can only pro- vide information on the outermost part of the asteroidal surfaces by measuring the NEA’s reflected sunlight. It does not mean that the elements on the surface are repre- sentative of the mineralogy of the subsoil. This problem brings together, as a first ap- proximation, all the asteroids, but it is par- ticularly concrete for those orbiting closer to the Sun, such as NEAs, which are sub- jected more than others to the action of space weather and micrometeoritic bom- bardment. Consequently, we will not be able to avoid the more intensive second phase of study of these objects by landing probes directly on their surfaces. This fur- ther step will allow us to collect samples for subsequent chemical analysis either with on-board or sample-returned laboratories, and will also provide detailed images of A lthough very imaginative, this illustration highlights the need to develop in parallel with the space mining industry an “in- dustry of trans- formation” and nearby use of re- sources extracted from asteroids. In this case, the raw materials ob- tained from a NEA are fash- ioned to give shape to a large spatial base. Deep Space Industries - Bryan Versteeg