Book Review: Cosmochemistry, by Harry McSween and Gary Huss

Chemistry is the study of the building blocks of the universe, and how they interact. But, in my experience, few chemistry texts spend much time explaining where all this stuff came from. There's a whole space science discipline called "cosmochemistry" that involves studying what planets, meteorites, and stars are made of, in what abundances, in order to tell the very earliest parts of the story of how we got here. But the work in this field has always been an impenetrable sea of letters and numbers to me.

Hap McSween and Gary Huss' Cosmochemistry is going to change that. The text is engaging and very accessible. Its introductory chapters provide a bridge between my last contact with chemistry (a college intro course) and the current state of the field. For example, the second chapter, on nuclides and elements, goes all the way back to the basics with definitions of atoms, isotopes, elements, and the periodic table. But McSween and Huss make it worth my while to read even this most basic review. They slice and dice the periodic table in ways different from a standard chemical textbook, comparing properties of the elements that are more meaningful in geological or astronomical contexts (and they explain why geology and astronomy require different takes on chemistry). A chapter on the origins of the elements explains how stars produce the stuff of the universe; the next two chapters examine which stuff our corner of the universe is made of.

There are chapters on presolar grains; meteorites; cosmochemical and geochemical fractionation; radioisotope chronology; volatile elements; asteroids; comets; planets (the Moon and Mars as case studies); and finally, a chapter drawing on all of the preceding work to tell the current stories for how the solar system came to be. An appendix provides brief explanations of a couple of dozen different analytical techniques commonly used in cosmochemistry. The authors do an excellent job of separating the factual (e.g. observed elemental abundances) from the interpretations that explain these observations, and they clearly indicate where there is more or less uncertainty about those interpretations.

The book's chapters are divided into many short sections with bold headers, ranging in length from a single paragraph to just a few pages, which makes it extremely easy to use as a reference. My one complaint here is that the index is not very detailed. But the chapters are so rigorously organized that perhaps a more detailed index would be redundant. Each chapter closes with several review questions helpful for checking your understanding of the chapter, as well as one or two mini-reviews of suggested works for further reading, and a list of references.

McSween and Huss tell lots of great stories about the people involved in solving some of the mysteries of the solar system's formation, both past and recent. For the most part, these stories are contained in boxes separate from the main text, giving the reader a choice between focusing on the main scientific point or reading about the often circuitous paths by which we have arrived (or not arrived) at explanations. Also contained in boxes are sections that drill down into interesting details that go beyond the scope of the main text  -- for example, oxygen isotopes in the Sun, or the common minerals in meteorites --  which is, I think, a great device for including useful information while preventing it from derailing a chapter.

When I reviewed Jay Melosh's textbook Planetary Surface Processes last year, I concluded:

Ultimately, this is a physics text, so it does not go into much detail on the chemistry of the solar system except where it most directly affects physical processes. I would love to see another book that takes the same organizational approach as Planetary Surface Processes, beginning with the composition of the nebula that formed the solar system, and walking through the chemical processes, major to minor, that differentiated this primordial cloud into the diverse compositions of planets, moons, cores, mantles, crusts, atmospheres, and dust that we see today. Who's going to write that one?

I want to thank Jennifer Piatek for pointing me to Cosmochemistry in a comment on that post! It's exactly what I was looking for. Now I need a textbook on space geomorphology, which I believe exists in Ron Greeley's posthumously published book, Introduction to Planetary Geomorphology, set for an April 30 release. I don't even need to review that to know it's going to be excellent...which is good, because I received a notice from Cambridge last week that my requested free advance review copy is "backordered"!