Hi readers! Heads up, this post will contain spoilers for Project Hail Mary by Andy Weir and the movie directed by Phil Lord and Christopher Miller. Currently you can watch the movie in theaters (April 2026) and can purchase the book from Amazon.
All Amazon links are affiliate links. This doesn’t cost you more but does help me with website fees. I was not compensated for this novel and all opinions are my own.
When I originally saw the first trailer for Project Hail Mary I was immediately intrigued… Ryan Gosling is a great actor, and my job is in the aerospace industry! Science fiction is not my favorite genre, so I hadn’t really heard of the book before. I quickly read the book before seeing the movie in theaters.
Synopsis (Movie):
A science teacher wakes up alone on a spaceship. As his memory returns, he uncovers a mission to stop a mysterious substance killing Earth’s sun and that an unexpected friendship may be the key. From IMDB.
Genre: dark comedy, epic, sci-fi epic, space sci-fi, drama
Rotten Tomatoes score: 94%
I put the ‘not’ in astronaut! I’ve never done a space walk, I can’t even moonwalk! I haven’t done any training, I haven’t done the whole… ..the pool thing!
Synopsis (Book):
Ryland Grace is the sole survivor on a desperate, last-chance mission – and if he fails, humanity and the earth itself will perish. Except that right now, he doesn’t know that. He can’t even remember his own name, let alone the nature of his assignment or how to complete it.
All he knows is that he’s been asleep for a very, very long time. And he’s just been awakened to find himself millions of miles from home, with nothing but two corpses for company.
His crewmates dead, his memories fuzzily returning, Ryland realizes that an impossible task now confronts him. Hurtling through space on this tiny ship, it’s up to him to puzzle out an impossible scientific mystery and conquer an extinction-level threat to our species. From Goodreads.
Genre: science fiction, fantasy, space, thriller
Goodreads score: 4.51
Human beings have a remarkable ability to accept the abnormal and make it normal.
**Spoilers Ahead**
Ryland Grace is a PhD biochemist who lives a normal life working as a public school teacher. Everything changes when it’s discovered that the sun is slowly dying. A small, alien organism called astrophage is “eating” the sun, causing it to slowly dim.
All of the brightest scientists in the world are tasked with solving the problem of why the sun is slowly emitting less light, what that means for Earth, and how can this be reversed/stopped. Ryland Grace is one of those scientists. Grace, along with two other astronauts are sent on a one way mission to Tau Ceti , a sun, light years away. This sun has a Petrova line, but it’s not dimming. The Petrova line is a bright, infrared line that represents the migration path of astrophage to a sun where it consumes solar energy, causing that said sun to dim.
However when Grace wakes up from his induced coma, he has no idea where he is, why he is in space, or even who he is. Also, he is the sole survivor onboard the ship – he’s a scientist not an astronaut! As the plot progresses, Grace slowly regains his memories and mission purpose. The ship continues to make its way towards Tau Ceti, when an abnormality appears on the radar – it’s another ship, one that is clearly not from Earth.
Grace and the unidentified spacecraft slowly approach one another and make contact. A friendship between the alien called “Rocky” and Grace forms. Both have been tasked with the seemingly impossible task of saving their home planet, and both are the sole survivors on their ships.
The two work together to determine why Tau Ceti has a Petrova line, but isn’t dimming. The friendship between two very different species is unique and comical at times. Grace brings his scientific background to the project whereas Rocky is an AMAZE AMAZE AMAZING engineer.
Main Differences
When comparing the book and movie, I want to start with the genre tags found on IMDB and Goodreads. The first tag IMDB lists is “dark comedy” and the first tag that Goodreads lists is “science fiction.” I was expecting a science fiction epic (think Dune 2021), but in space and no intergalactic wars. Instead, I got a lighthearted comedy. EARTH’S POPULATION DYING ISN’T A LIGHT-HEARTED TOPIC. Again, for theaters this worked, but if you are a die-hard fan of the book, it may miss the mark.
Because the movie goes for a more light-hearted role, some characters from the book are cut out where others are expanded upon. I think the movie did a great job at casting, but I would’ve liked more interactions with the other astronauts/scientists.
The movie leaves out a lot of information compared to the book. The movie run time is 2 hours and 36 minutes and the book has 496 pages and 30 chapters. I understand why some content had to be cut because the movie was originally over 4 hours long before editing. I wonder if we will ever get a director’s cut of Project Hail Mary that is 4 hours long.
Rocky watch whole crew die. Could not fix. Grace say Grace will die. Rocky fix.
A big part of the book that was left out was the coma resistant genes. This really really annoyed me. In the book, the way the astronauts are chosen to go on the Project Hail Mary mission is through genetic testing. In order to survive the multiple year long flight, the astronauts are put into a coma. The longer a person is in a coma, the more likely it is they won’t wake up. Through genetic testing, candidates for the mission were tested for the gene that made them more “coma resistant” and bettered the chances of them surviving the flight to Tau Ceti. When Grace was volun-told that he was now going to be on the flight crew there really weren’t many people with the necessary background AND the coma resistant gene. Not including this in the movie was more than likely due to time constraints, but I feel like this was a big part of the book and a major plot point.
The book posed an interesting question/dilemma of how far we will go in order to save the human race and the impacts that has. When the temperature of the Earth changes just by a few degrees, there are major impacts to Earth’s ecosystems. Many animals will go extinct. In order to stave off human extinction for as long as possible, irreversible damage was purposefully done to the Earth in the book. Ice caps in Antarctica were blown up to release methane gas and create a greenhouse effect to keep the earth warmer for longer, giving the mission a few more years times before the human population goes extinct. Hundreds of acres of the Sahara Desert were paved to collect enough energy to breed enough astrophage for Hail Mary’s fuel.
“We’re looking at extinction of many species, complete upheaval of biomes all over the world, major changes in weather patterns— Humans,” Stratt said. “I want to know how this affects humans, and when. I don’t care about the mating grounds of the three-anused mud sloth or any other random biome.“
Movie Pros
Cinematography: The cinematography is breathtaking, and seeing it theaters was nothing shoer of amazing. Rocky’s spaceship was unlike anything I could have imagined myself when reading the book, and it was a perfect representation of advanced engineering of Eridians. Many people online have said you need to experience the movie in Imax because it is just that good. Unfortunately, the closest Imax to me is about an hour away AND Imax movies make me nauseous.
Soundtrack/score: The movie score was amazing and really added an additional level of experience.
Sandra Hüller’s character, Eva Stratt, performs a karaoke version of Harry Styles’ “Sign of the Times”. This song was selected by Hüller to represent an emotional final goodbye. It became a key scene in the movie (although this scene was not in the book), and made the character Stratt seem less cold and more human.
Book Pros
Every little detail is explained: Andy Weir did a great job researching and explaining all the science in the book. The additional science really puts into perspective how critical the Project Hail Mary mission is to saving Earth’s population.
Once again I’m struck by melancholy. I want to spend the rest of my life studying Eridian biology! But I have to save humanity first. Stupid humanity. Getting in the way of my hobbies.
Flashbacks: The flashback scenes were my favorite part of the book! There are more flashbacks in the book compared to the movie. The big “revelation” Grace had was more impactful in the book than the movie because as a reader there was more background/flashback information.
Grace’s inner thoughts: The book is told from Grace’s perspective and his inner dialogue is brings comedic relief to the doomsday situation. The book really showcased how smart Grace was. From the movie I kept thinking that it was Ken (from Barbie) cosplaying as an astronaut but without any shirtless scenes. I didn’t feel like the movie’s portrayal as Ryland Grace being this super smart PhD biochemist landed due to most of the science from the book being cut out.
I’m a scientist! Now we’re getting somewhere! Time for me to use science. All right, genius brain: come up with something! …I’m hungry. You have failed me, brain.
Movie Cons
Need more background: I am someone who needs and enjoys background information. I still understood what was going on (for the most part), but some things didn’t land as well when comparing it to the book.
Pacing: The pacing in the end and beginning of the movie was a bit slow for me. I know that many scenes had to be cut to make it a more palatable length of just over 2.5 hours, but I feel like at least 20 more minutes could have been shaved off.
Book Cons
Dry/a lot of science: Yes, this is a pro and a con. There were some parts of the book that just seemed to drag on and on because of Weir explaining every little thing. When I first picked up this book I ended up DNFing at about 30% because I was so bored. When I picked it up the second time I took more breaks when reading it and that helped me get through it.
Imagining the visuals: I literally have no idea what the inside of a spaceship looks like. I did a lot of googling to figure out what different parts of a spacecraft looked like and different lab instrumentation. However, Rocky from my imagination vs. Rocky from the movie?? Spot on.
Bookmark, Watch, or Bin it?
Conclusion: Watch then read
If this genre interests you, I say watch the movie first and then read the book. The movie glosses over a lot of the “science” details. If you want a more in-depth understanding of the science behind all the space stuff, then you will get that in the book. The movie is lighthearted and comical at times when the book is drier.
To me, the movie and the book have completely different vibes, and that really threw me off. I also went into the movie thinking I wasn’t going to like it, so I wasn’t completely *unbiased*. The film received high praise from critics and audience members that I was truly expecting a masterpiece, but that fell short for me. The book also received many positive reviews on Goodreads, but it missed the mark for me as well.
Fun Extra Tidbit
NASA’s Artemis II launched on April 1, 2026 for a historic 10 day mission to the moon and back with a crew of 4 astronauts. This was the first crewed flight around the moon in 53 years!
We will explore. We will build. We will build ships. We will visit again. We will construct science outposts. We will drive rovers. We will do radio astronomy. We will found companies. We will bolster industry. We will inspire. But ultimately, we will always choose Earth. We will always choose each other. – Christina Koch
Thanks so much for reading my article comparing Project Hail Mary the book and movie! Now it’s your turn! Have you read this novel or any others by Weir and if so, what are your thoughts? Have you watched this movie? Please feel free to share in the comments below!
Happy reading (and movie watching) ☺️
