Rasmussen, Seven. Cloudy With a Chance of Starships. Princeton University Press. 2026. ISBN13: 978-0-069-124622-2. $29.95.
The year was 1950 and, at a lunch meeting in Los Alamos, New Mexico, Enrico Fermi asked a famous question regarding extraterrestrial life: “Don’t you ever wonder where everybody is?”
Astrobiologist and author Seven Rasmussen waits until page 137 of her book Cloudy with a Chance of Starships to present Fermi’s question. I think it’s a great decision…the question is presented about halfway (physically and narratively) through the book and provides a useful touchstone in the search for extraterrestrial life.
Dr. Rasmussen focuses on the Drake Equation, which attempts to establish the probability that life exists on another planet within our Milky Way galaxy. The equation itself can be expressed as a product of seven values:
- The yearly rate at which new stars are born
- The fraction of stars that host planets
- The number of planets per star that could potentially host life
- The fraction of planets on which life evolves
- The fraction of life that becomes intelligent
- The fraction of intelligent beings that develop interstellar communication
- The average lifespan of a technological society
Simple, right? Absolutely not. As Rasmussen points out, we know a lot about a couple of these variables (star birth rates and the fraction of stars that host planets), a bit about how many planets could potentially host life, and discouragingly little about the rest.
The author takes great care to provide the background knowledge and context for readers to grasp the implications of the Drake Equation and the information required to even begin to evaluate it. One could describe the Drake Equation reasonably well in a 3,000-word article, but Cloudy with a Chance of Starships assumes nothing beyond an intelligent reader. Rasmussen includes topics such as star and planet formation, water as a basis of life, amino acid formation, protein formation, biosignatures, technosignatures, various and sundry ways for civilizations to die, and the future of astrobiology.
I enjoyed Cloudy with a Chance of Starships, but my heart sank a bit when I saw the book’s title in the Princeton University Press catalog. The animated film Cloudy with a Chance of Meatballs, based on a short story of the same name, was surreal fun that intended to entertain rather than educate. I worried the book would try too hard to be cute and funny, but Rasmussen pulled it off.
Humor is a ridiculously individual thing, but I quite enjoyed lines such as “Here on Earth, we have millions of different species, but only one has invented the air fryer.” That bit landed on page 137, two paragraphs below Fermi’s famous question. Rasmussen liberally sprinkles her prose with jokes that I’m happy to report pretty much always work and don’t seem forced. I’m glad. Getting the humor wrong would have undone the terrific effort to explain Drake’s Equation and provide sufficient context to understand its context and implications.
Sorry...I almost forgot to mention that Rasmussen does provide and explain the current best guess as to the probability of at least one other intelligent civilization in our Milky Way galaxy. It would be unkind to spoil the surprise, so I’ll let you read Cloudy with a Chance of Starships and discover it for yourself.
Highly recommended.