A City on Mars
by Kelly and Zach Weinersmith
Summary
The Weinersmiths began this book as space settlement enthusiasts, intending a cheerful guide to humanity's multiplanetary future, and their research talked them out of it: the book they actually wrote asks the subtitle's three questions, can we settle space, should we, and have we really thought this through, and answers, roughly, not soon, not yet, and absolutely not.
The demolition is conducted with jokes, cartoons and footnotes, which makes its thoroughness sneak up. The biology first: almost nothing is known about human reproduction off Earth, radiation and low gravity are unsolved problems for bodies designed by neither, and a settlement that cannot safely gestate children is a very expensive Antarctic station. The habitats: Mars is a frozen poison desert, the Moon worse, rotating stations unbuilt at any scale, and the closed loop ecologies that would feed a colony have failed at every trial, Biosphere 2 recounted in loving detail. The law: the Outer Space Treaty forbids the national appropriation everyone's business plans quietly assume, and the plausible paths around it look less like the frontier than like a scramble, company towns without exit, sovereignty crises with nukes. The sociology of small isolated populations completes the case.
The stance stays affectionate throughout: they want the future, which is why they audit it, and the book ends with a wait and grow up program rather than a never.
Around four hundred and forty pages, the funniest rigorous book on any shelf it shares.
Best for readers who love space enough to want the actual obstacles, catalogued by sceptics who came as fans.
Historical Context & Significance
A City on Mars won the Royal Society Trivedi prize in 2024 and, months earlier, the Hugo Award for best related work, a pairing that measures its odd, perfect audience: honoured by the scientific establishment and by science fiction fandom for the same act of telling both their communities to slow down. It was also a New York Times bestseller.
The authors are a household division of labour: Kelly Weinersmith, a Rice University biologist, and Zach Weinersmith, creator of the webcomic Saturday Morning Breakfast Cereal, whose earlier collaboration Soonish had road tested the format of enthusiasm audited by evidence.
The book landed in the middle of the billionaire space settlement boom and became the standard sceptical citation against Mars colony timelines, invoked across policy debates and discussion threads alike; the space advocacy community produced rebuttals, the authors engaged them cheerfully, and the argument it organised, settlement when against settlement whether, is now conducted largely on its terms.