“The Once and Future Moon”by Paul Spudis. Published in 1996 by the Smithsonian Institution Press, it weighs in at 308 pages all-in. No errors noted.
I decided to re-visit this one for a review when I realized that I couldn’t remember when I first read it, having read so many Moon books subsequent to this one. Paul autographed the copy in the Lunar Library on October 17th, 2002, which IIRC was at the World Space Congress, where he had just gone head-to-head with Bob Zubrin on the relative merits of our Moon and Mars respectively. So I would have read it before then. I’m pretty sure it was back in ’99 that I picked it up, back when I was still working the Wall Street Desk as a credit analyst for BNP, juste nouvellement BNP Paribas. This is an important point that will touched upon later.
Probably one of the better first chapters amongst the many Moon books, because instead of starting out with the cultural legacy of our Moon in human history, it instead starts out with the legacy of those who have mapped our Moon, a worthy scientific endeavor that lays the groundwork for future discoveries. He works his way through an almanac of facts, from surface temps to min/max distances and the effects of the difference in inclination of the Moon’s orbit around the Earth, with the orbit of the Earth around the Sun which creates the plane of the ecliptic. Eclipses occur only when the Moon is in the plane of ecliptic, hence the name. The author also looks at the development of science that relates to our Moon, and the big theories of the day right before the Big Event that would show whose theory had the ‘Right Stuff’.
In chapter two we look at the physical characteristics of the Moon, it’s “jagged and scarred” surface and the many features that create such a forbidding landscape not for the faint of heart. True to his background as a geologist, Dr. Spudis presents a concise but thorough backgrounder on the physical forces that shape the features we see. Craters, rays, basins, rings, ejecta blankets, lava flows, lava blankets, lava shields, scarps, rilles, grabben, fissures, swirls, and more. He also touches on how geological mapping has led to an understanding of Lunar history.
Chapter three brings us to the modern era of Moon exploration. He walks through the contributions of Ranger, Surveyor and Lunar Orbiter, the originals pathfinder robots that gave us the lay of the land on the Moon that contributed significantly to Apollo efforts while deriving important scientific knowledge from the increasingly sophisticated instruments on board. He then looks at each of the missions, but from the perspective of how they contributed to our understanding of the Moon’s development and history. He even looks at Russian efforts and how they contributed to piecing together the puzzle.
The next chapter is entitled “A Fall of Moondust”, in tribute to the classic sci-fi story, and tells the story of the regolith, the layer of fine dust that scientists have long known covered the surface of the Moon. How did they know? Were the Moon a solid rock, then there would be a point directly under the Sun that would be brighter than surrounding areas, a specular reflection. Instead, the jagged shape of the particulates scatters the light,and the finer the particles the more that happens. Of course, the same impacts that bust up the rocks into smaller and smaller rocks also melts rocks, and throws that melted rock around, giving us agglutinates, or small chunks of glassy material. There are even bits of meteorites in the regolith, and these are discussed also. There are also some nice color plates.
Of particular interest to those who live in view of the near side of the Moon are the dark areas of the mare, and in the next chapter Dr. Spudis relates what scientists understand about the process of Lunar volcanism and the lava flows that created the mare. These were found to be basalts, rocks that are rich in iron and magnesium. One of the cool effects of volcanism is fire fountains, which give us glass beads (that turn out to have more water in them than previously expected). We explore how the basins filled, how the lava flows sculpted the landscape, and how tectonics further shaped things.
The lighter-colored parts of the Moon are the ancient highlands, which date, for the most part, to the formation of the original crust of the cooling Moon (probably – it hasn’t been conclusively proven that the Moon was entirely molten back at the beginning, but things point to that being the case). In this chapter we’re told of the breccias, composed of bits and pieces from all over the Moon. This leads to an extensive discussion of how the crust may have formed, including some discussion of the KREEPs.
Travelling further back in time, the next chapter delves into the varied theories regarding the origins of the Moon, and how none of them really fit. Luckily, the accumulation of data from various Lunar missions pointed to an explanation that tied together various elements from the different Moon origin theories, the appropriately named Big Whack hypothesis. Still, the author notes that the theory is not conclusive, just the best explanation we’ve got so far.
Subsequent to Apollo, scientists realized they could really use a more comprehensive map of the Moon, something that could be provided by something like a Lunar Polar Orbiter. Unfortunately, the science community was anxious to apply the space science lessons from Apollo to the rest of the Solar system, and Lunar science quickly fell to the wayside. Some attempt was made to incorporate Moon science into the Space Exploration Initiative, but that of course went nowhere. Meanwhile, out of the spotlight the author was working with a team at the Strategic Defense Initiative Organization to fly a spacecraft to test out some cutting edge instrumentation. It turned out that a swing by the Moon would be a great way to test out the probe before sending it out to visit an asteroid. The results from Clementine turned out to be far more surprising than anticipated.
These results help make the case for the next chapter, “Why? – Four Reasons to Return to the Moon”, which break down as:
Â· A Natural Laboratory for Planetary Science
Â· A Platform to Observe the Universe
Â· A Source of Materials and Energy for Use in Space and on Earth
Â· A Place to Learn to Live and Work in Space
This may have been the chapter that first got me hooked on the idea of Lunar development. For the first time, I was reading scientific writing that supported the idea of commercial development. That was something that really resonated with the banker in me.
In the next chapter, we look at the “How? – Steps in the Exploration and Use of the Moon”, using a step-by-step process to establish a firm foundation of knowledge:
Â· Orbital Surveys
Â· Fixed Stations
Â· Surface Network
Â· Surface Rovers
Â· Sample Returns
Â· Human Exploration
Seems pretty straightforward to me. In each succeeding step you build upon previous successes, leading eventually to a permanent human presence on our little sister in space.
Having outlined so many compelling reasons to return to our Moon, the next chapter begs the question “When? – What’s Holding Us Back?” Here, Dr. Spudis looks at many of the rationales and motivations, as well as mechanisms, often offered for making Lunar development happen. He offers his own suggestions, but you’ll have to read the book yourself to find out what they are.
We finish up with appendices on basic Lunar data, chronologies of robotic and human missions, some handy metric conversions, some places to visit to quench your thirst for space knowledge, a thorough glossary including some mineralogical terms (thank goodness), a comprehensive thematic bibliography (many, but not all of which are in the Lunar Library), and an index to round out its 308 pages.
This book remains to this day an excellent starting point on the path of Lunar interest. While the events of the last two years do provide an opportunity for an information update (especially given that Dr. Spudis has been involved with both the Chandrayaan-1 and Lunar Reconnaissance Orbiter), the fundamental theses of the book remain important. While science rich, it nevertheless remains accessible to people outside the rather insular field of space science, such as bankers like yours truly. That the contents remain topical even today is testament either to the forward-thinkingness of the author, or the relatively slow pace of development in Lunar science (at least until recently), or perhaps both.
Just as good a read the second time around, I’ll give this one a Full Moon.