Xenonite

A month ago, in my quantum chemistry class, I did a “fun” segment on the ubiquity of hydrogen in the universe. We had finished solving the Schrodinger equation for the hydrogen atom, discussed the representation of orbitals, and talked about spin and the Zeeman lines. To wrap up, I told the students about SETI, the movie “Contact”, how we might talk to ETs on the hydrogen 21-cm line, and what information scientists from different worlds might communicate to each other to establish a baseline. After class, one of my students asked me if I had read The Three Body Problem (I had) and Project Hail Mary (I hadn’t). He said I’d really enjoy the latter without giving away the plot.

 

I looked up the book. The author is Andy Weir, and I enjoyed reading The Martian. The blurb sounded familiar – astronaut lost alone in the depths of space – which is why I hadn’t considered it previously. But after reading some reviews, I decided it might be interesting enough to give it a whirl. So I borrowed the book from the library, then waited for Thanksgiving Break to devote a block of time to immerse myself in a good book.

 

I’m pleased to say that Project Hail Mary is very good; better than The Martian given my research interests and spending much of my working hours prepping for biochemistry class. Yes, the protagonist is in a related situation. And yes, the protagonist has a personality similar to Mark Watney. But there are plenty of differences that make this an engaging story. I won’t give away the plot, but I will say that that Weir serves up interesting and thoughtful stuff on biology, chemistry, physics, mathematics, and climate science. The scientist in me loved geeking out on the material. The speculative biochemistry got the gears in my mind turning! More on that in a moment.

 

A chunk of the story has to do with what might happen when one comes into contact with an extra-terrestrial species. How might scientists from both realms communicate even though they may have different umwelts? Project Hail Mary is more well-grounded in science than The Arrival or Contact (my only experience is with the movies rather than the sci-fi novels they were based on). Weir does a good job here. But for me that wasn’t the best part of the book.

 

As a chemist, I was intrigued by a new material, xenonite. At least that’s what the human protagonist calls it because he could detect xenon as one of the heavy elements in it. Xenon, as my introductory chemistry students know, is a noble or inert gas. It shouldn’t do anything! But in G-Chem, I surprise them with a few noble gas compounds of xenon and krypton as they work on Lewis structures. While some of the physical properties of xenonite are described, Weir leaves the chemical properties a mystery although clues suggest that lighter elements with polymeric structure are part of it. It can be good storytelling to keep the science a bit vague.

 

Xenon means strange. Or fittingly: alien. Weir’s speculative descriptions of xenobiology were fun to read. What sort of body and what sort of biochemistry should the alien species have given the environment of its home? How might it have evolved? What are the possible building blocks at higher or lower atmospheric temperature? How might temperature affect the building and functioning of an organism? What about gravitational force? None of this speculation is new to sci-fi, but I could see where Weir started with reasonable biochemistry and then extrapolated to provide not unreasonable speculation. I’d say he does a good job overall in thinking about what chemical elements are important, how they might be acquired as food, the role of energy transduction, and how evolution plays into all of this.

 

All this got me thinking about what chemistries are available in different environments and where an organism might be able to exploit energy differentials. Is water required? What about ammonia? Or acetylene? Or cyano compounds? Or formamide? Why is phosphate the universal energy “carrier”? How about sulfur compounds? I could envision teaching a whole new class surrounding this question! But for now I think I will settle for coming up with some clever examples for my classes next semester – I’m teaching lots of thermodynamics and kinetics both at the G-Chem and P-Chem levels. I can expand on the examples I use when discussing fuels and energy transduction. I hope the students find such speculation fun. I certainly did. And that’s why Project Hail Mary was very well worth the read!