Choosing a New Home: How to Determine Which Asteroid to Settle UAE MBR Settlement Challenge 2018 Project Report J.L. Galache, PhD Aten Engineering, Inc. This project received seed funding from the Dubai Future Foundation through Guaana.com open research platform. Contents Introduction 1 WeRoam......................................1 Beyond the Horizon . .1 Asteroids, the Breadcrumbs of the Solar System . .4 Motivation and Goals 7 Method 9 Sources of Data . .9 A Matter of Time vs Energy . .9 A Matter of Some Gravity . 11 Search Parameters for Candidate Asteroids . 12 Small Settlement on Small NEA . 12 Large Settlement on Large Asteroid . 12 Mining Settlement on NEA . 13 Results 15 Conclusion 19 Bibliography 21 Appendix – Lists of Candidate Asteroids 23 iii Introduction We Roam The human species has few characteristics that are unique to it, setting it apart from other species on our planet. Humans are not the only animals to use tools, or lan- guage, create societies, feel sorrow and joy, nor take care of our young, wounded and elderly. Sadly, we are also not the only ones to murder and wage war. But we are the only ones so far to write, clothe ourselves, blush, and purposely interrupt our natural sleep to wake up earlier than we would otherwise. While these and other traits have undoubtedly contributed to our perceived success with respect to other species, it is one characteristic in particular which has enabled all our other traits to shine: Our restlessness. The fossil record and DNA analysis show that al- ready 2 million years ago some of our earliest human ancestors, the Homo Erectus, had left their birthplace in Africa and established themselves throughout Europe and reached as far away as China [16]. Humans have ultimately established them- selves on every continent of our planet, even when the conditions were so harsh it would have made sense to find another land to live in. This could be because hu- mans have another unique characteristic: We can make our home anywhere, and the decision of where this is does not have to depend on the local climate. We are adaptable, we are hardy, and we are stubborn; if we have decided to make a life somewhere, we will do just that. Not all humans are restless; some like to stay just where they are, which is precisely why we have spread throughout the globe. Through circumstance or de- sire, our ancestors travelled the world, leaving individuals behind to create camps, which became towns, cities, countries, empires. And all throughout the millennia, a subset of people kept travelling and exploring and leaving footprints where none had been left before. Now that we have mastered every climate, every latitude, and every height, it is only natural that some of those restless souls among us look not towards the horizon for challenges, but upwards, away from the safety of Earth’s surface, with its fertile lands, plentiful oceans, and nourishing atmosphere. The allure to keep moving to new lands is as strong now as it was millions of years ago. We should not wave it aside or ignore it; it means we are still human! Beyond the Horizon Where in the Solar System would we live were it not on Earth? Mars has long been a favourite of crowds and science fiction writers alike; something about it is alluring, even if we can’t quite figure out what. Its rusty desert landscape is reminiscent of some areas on Earth, and it also hosts an atmosphere (albeit much 1 2 Introduction thinner than Earth’s) which, unlike Venus’s, is transparent, and even hosts familiar clouds floating by on the wind. Of course, the temperatures on Mars are quite extreme: At its warmest, on a Summer day it can reach 20◦C, while in Winter or at nighttime temperatures can plummet to −150◦C. Mars also happens to be quite close to Earth (in astronomical terms) with a one-way trip taking about 8 months. Notwithstanding all the challenges of living on Mars, its appeal remains strong and, apart from the Moon, it has been the favourite destination for human exploration craft since 1960, with 46 missions having successfully been launched towards the red planet since then, and seven more in development and planned to launch within the next few years [14]. The main driver, at least publicly, for many of these missions is the search for life on Mars, or some evidence that it once existed. Thus, Mars has been ripe for science fiction authors to use as their backdrop, or even a protagonist, in their stories. As early as the 19th century, authors were creating tales of trips to Mars, usually recounting the adventures of Earth travellers as they encounter the inhabitants of the red planet [4]. Edgar Rice Burroughs’s popular Barsoom series (11 books written between 1912 and 1964) proves the long- lasting interest of this genre, which inspired the likes of Carl Sagan to one day undertake the scientific exploration of Mars1. Starting in the 1950’s, as scientific knowledge of Mars was beginning to make an inhabited Mars an unlikely scenario (which was confirmed in the 1960’s and 70’s by NASA’s Mariner and Viking programs), fantasy and science fiction authors began incorporating this into their writings and new themes appeared, such as how to settle an empty planet, the challenges of surviving in such a harsh environment, and whether Mars should be terraformed or not. These themes have persisted until today, giving us such science fiction classics as Kim Stanley Robinson’s Red Mars, Green Mars, and Blue Mars trilogy in the 1990’s, all the way through to 2011’s The Martian, by Andy Weir, which could be classified as “realistic sci-fi”, portraying the struggles of an astronaut marooned on Mars and having to survive until a rescue mission arrives. It was only natural that when motion pictures were invented Mars would be- come a topic of this new medium. Indeed, in 1910 one of Thomas Edison’s pro- duction companies created A Trip to Mars, an almost 5-minute film that portrays a scientist floating to Mars after covering himself in antigravity powder2. Many a Mars-themed story or novel was adapted to the big screen: H.G. Wells’s The War of the Worlds has been adapted several times, Philip K. Dick’s We Can Remember It for You Wholesale became Total Recall; A Princess of Mars was adapted as John Carter; the hugely successful The Martian movie based on the eponymous novel by Andy Weir, etc. [17]. Many more were standalone movies, with over 30 being listed in reference [13]. It is therefore not unexpected that the likes of Elon Musk would grow up dreaming of settlements on Mars and, upon finding himself in a position to make that dream come true, would act upon it and create a series of companies to prop up the endeavour. NASA has long spoken of sending humans to Mars, but Musk actually started working on it. That there is interest beyond the confines of scientists and engineers in going to Mars was made apparent in 2013, when Mars One3, a private Dutch organization 1https://youtu.be/-5fbHkGpILc. 2https://youtu.be/np7VImsSMQM. 3https://www.mars-one.com. Beyond the Horizon 3 proposing to send people to Mars on a one-way trip, received over 200,000 initial submissions of interest from people around the world willing to make that one- way voyage [11]. Much of the interest in settling Mars has stemmed from a desire for adventure, but more pragmatic ideals are coming to the forefront, such as those who see Mars as a backup to Earth, a place where the human race, or at least a small portion of it, can survive in the event of a catastrophic disaster wiping out all life on our home planet. But would not the Moon make for an easier backup location? It is a mere 3 days travel away, compared to 8 months for Mars, and communications back and forth are almost instantaneous, whereas a radio message to Mars can take anywhere from 4 to 20 minutes to arrive there, and just as long to return. The Moon does have a “day” that lasts about 14 Earth days, and a night lasting equally long, while Mars’s day is a familiar 24 hours and 37 minutes long. There are pros and cons, but this has not stopped many from dreaming about lunar bases and frequent trips to the Moon, effectively dividing up Space enthusiasts into two camps: Team Moon and Team Mars. The Moon has had its fair share of literature and cinema dedicated to it, not to mention song and mythology. It has also fed the imagination of engineers and scientists, who have spent decades dreaming up permanent bases on the Moon, with both scientific and commercial purpose. Now these dreams seem closer than ever to becoming reality with both NASA and ESA emphasizing lunar projects in their near-term plans [12, 15, 2], with the added novelty of ISRU (In-Situ Resource Utilization) and private-public partnerships being essential components of their strategies. Even Venus, with its suffocating temperatures (around 450◦C at the surface) and corrosive atmosphere (mostly carbon dioxide with clouds of sulfuric acid) has been the subject of settlement plans, though human outposts would consist of air- filled structures, floating high up in the atmosphere, where temperatures are a balmy 20–30◦C [5]. So far we have only discussed settlements on planetary bodies, because, as Isaac Asimov once pointed out, we are “planetary chauvinists” [7].