Fans pick 59 books like Protector

Isaac Asimov rarely wrote about aliens, but this Hugo and Nebula award-winning novel contains an astounding thought experiment, not only imagining a truly alien species but placing them in a different universe with different physical laws from our own.

I first read this novel as a teenager and was blown away by Asimov’s ability to make me understand and care about the fate of such vastly different alien creatures that possessed three distinct sexes and derived their life energy from photosynthesis.

The fact that the novel inextricably links the fate of these creatures with the fate of our own universe gave me a greater appreciation of how truly diverse life can be. A fact–along with the lessons I learned from the other novels listed here–that continues to inform my own writing on aliens and alien cultures. 

I found this book, the first of four in the series, to be fascinating in its portrayal of a race of intelligent, upright-walking lions. Cherryh’s ability to invent believable and fully fleshed-out alien races is delightful.

In this series, humans are the aliens. I loved how Cherryh made the reader root for the lions and their strange but understandable culture. It's a great concept by a great writer.

If it’s hard to make readers side with spiders, what about plants?

The planet on which an unlucky group of humans are stranded in Semiosis is indeed home to sentient plants that see humans as just another resource. But this isn’t some Day of The Triffids monster tale. The plants can’t move anything like humans can, which, in the hands of a lesser author, might make for quite a static, boring story.

Burke demonstrates her boundless imagination by taking the reader into the "mind" of the plant, seeing the world, its threats, and resources in a completely different and plant-like way and bringing a sense of urgency as the survival of plant and humans alike become bound together.

It’s a fascinating read, and the follow-up, Interference, is just as good. 

As a big fan of xenofiction, I appreciated that large parts of the book were written from the perspective of non-humans. I loved the author’s imagination, which, while innovative, never strayed into the implausible.

I was very interested in the timespan of thousands of years and the concept of accelerated evolution, and I found the intelligent, massive spiders to be both creepy and fascinating. For me, Children of Time was a good page-turner and a great read.

Another book I read when I was young and never forgot, James P. Hogan's debut novel takes us once again to the Moon. Inspired by Clarke's 2001, it tells a much different story in which Earth's Moon originally orbited another planet entirely. When its first planet was destroyed, the debris became the asteroid belt between Mars and Jupiter, and the Moon was captured by Earth's gravity. And how did we figure this out? Because our own astronauts exploring the Moon find a long-dead, spacesuited astronaut who is very human but has technology beyond ours. Reverse-engineering that technology puts us closer to exploring beyond our solar system, and it turns out the captured Moon also had an impact on our ancient history. I love this book for its grand, compelling ideas.

This science fiction novel, written by Daniel Abraham and Ty Franck under the pen name James S. A. Corey, was the beginning of the Expanse series (now totaling 9 novels and additional stories). It is one of the best space science fiction novels of the 21st century and became the basis for one of my favorite TV/streaming series, The Expanse.

The books dive deep into the political, social, and cultural complexities of sending humans to live on the Moon, Mars, and the asteroid belt, and it’s a nuanced reflection of our current ideas and ambitions when it comes to spaceflight. I am particularly drawn to the depiction of humans who, after multiple generations off Earth, consider their primary identity to be Martian.

The search for life outside the Earth is NASA’s greatest quest, and this book will bring you up to speed on it. Just a few decades ago, scientists thought life arose on the Earth in shallow seas, warmed by the early sun and zapped by energy-producing lightning. The best place to look for alien life was on Mars, where bacterial life may have formed in the shallow pools that covered the young Mars, and then hunkered down in subsurface spots of Martian water and ice as these pools evaporated. Scientists now suspect life arose in warm vents deep in the Earth’s ocean. Subsurface oceans in the moons of the outer Solar System may contain similar vents that serve as breeding grounds for primitive life. Kevin Hand describes NASA’s current missions and instruments to find this life in alien oceans.

“Are we alone?” An age-old question that we may never answer. Andrew May walks us through the scientific study of whether there might be life elsewhere in the universe, and how we might identify it. And by “scientific study,” I mean actual scientific investigations, not wishy-washy sci-fi fluff. The book is both inspiring and terrifying, because the immense distances in space and time make you realize that intelligent life is both incredibly insignificant and incredibly precious.

Carl Sagan was that most unusual of creatures: a top scientist who was also a lyrical writer. In an era when scientists were still wary of dealing with the press – an aversion that he helped overturn – his books were particularly influential in promoting the search for extraterrestrial life, both on the planets of our own Solar System (notably Mars) and on planets of other stars. In nearly 40 short, varied essays, The Cosmic Connection outlines our links with the cosmos around us, raises the possibility that we are not alone, and discusses what we might do if an extraterrestrial contact were to be received.

This is hefty, recent, authoritative, and well written (the author’s CV includes a Pulitzer Prize nomination).

Over a lengthy historic account, he spins the twin stories of the search by scientists for extraterrestrial life and the – usually – amateur search by ufologists for evidence to support their claims that aliens are already visiting us. Garrett Graff explores the contradictions.

He is clear and concise on the strength and weakness each side’s efforts, and insightful in those moments when both sides have briefly collaborated. For a beginner to the subject who wants the shortest route to becoming truly knowledgeable, this is the perfect primer.