Project Hail Mary: What Changed from Book to Film
By Rebekah Edwards
Somewhere in the back half of Project Hail Mary, Ryan Gosling takes off his glasses and hangs them off his ears, upside down, below his chin. If you find that confusing, fellow glasses-wearing human (as I assume you are), you’re not alone.
He invented that move himself. By the time someone told him that no glasses-wearer in human history has ever done this, they’d filmed too many scenes to go back. 😂
I love that. Not the move — the move is deranged — but the fact that it’s in the finished film anyway, a little monument to commitment.
My family and I read the book, watched the movie, and then argued about both for an hour on our podcast. (And when I say “watched the movie,” I mean I saw it 5 times in the theatre, including one session with Mom listening to the full director’s commentary. Commitment, remember?) What follows is the full accounting — every real difference we found, sorted the way we sort everything: characters, setting, plot.
Spoilers ahead for both the book and the movie. All of them. Including the ending. You’ve been warned, and honestly, you clicked on an article with “every difference” in the title, so I think you knew.
PS: If you’d rather listen or watch us talk about this in a patently ridiculous amount of detail, you can do so on YouTube or your favorite podcast app.
1. Big character changes
Stratt got sanded down.
Book Stratt commandeers courtrooms, threatens people with the full weight of every government on Earth, and tells a man he lives at the project now and, NO, he may not go home.
Movie Stratt still runs the world, but the sharpest edges — the court proceedings, badgering the prison guard, the harsh conscriptions — are gone.
In exchange, we get a karaoke scene, which wasn’t in the original script at all: it was added after Gosling heard Sandra Hüller singing, and the Harry Styles pick (“Sign of the Times”) seems to have been hers. I’m not proud to admit the trade mostly works on me (and the family mostly agreed).
Officer Carl exists now.
Played by Lionel Boyce. He’s a pure invention of the film, but a gold choice for giving Grace a chance to show some personality early on after eliminating his unhinged internal monologue we got from the book.
(”We’re fathers, Carl” will continue to be one of my favorite quotes of the entire film. I make no apologies.)
The crew’s presence shrank.
Ilyukhina, DuBois and Shapiro, Yao — the book gives them real time, and the movie mostly gestures at them on its way past.
This was a harder change to swallow, but understandable. Mom and I still cried during Grace’s send-off to Ilyukhina and Yao. (And, to be honest, I absolutely did not miss the weird sexual disclosures from DuBois and Annie Shapiro.)
Grace’s fall was… different?
This was our dinner-table fight. The book’s version of Grace’s confession, learning that he was a coward unwilling to forgive Stratt… gutted me. Gutted US. I was so angry the first time I read through it in the novel that I had to put it down for a few hours.
The movie plays the same beat with a lighter touch, and depending on which of us you ask, that’s either a mercy or a minor crime. (I’ll let you guess which parent voted which way.)
I, in particular, felt like watching Grace comedically jump on cabinetry downplayed the gravitas of what that moment in the book made me feel. However, I think a wide audience might have had a more difficult time with that murkier version of Ryland Grace, so I can’t really blame them for the adjustment.
2. Setting
The ship got an upgrade. (That phrase is the understatement of the year.)
The film’s Hail Mary is much larger than the book’s, redesigned top to bottom, with a whole “mental health bay” built for looking at Earth. The book’s original ship design does sneak on screen — watch for it when Grace first gets introduced to the project.
That opening ocean is a callback in disguise.
The beach Grace “sits in” near the start of the movie, watching someone approach? That’s the beach the Eridians rebuild for him, and the man walking his way is… himself! The film opens inside its own ending and dares you* to notice on the first watch.
*We did not notice on the first watch.
Adrian got a glow-up.
The planet has an entirely unique look on screen. And remarkably, no green screens were used in the whole movie (which you can feel, even when you can’t say why).
If you did not feel something heal deep inside of you while watching Ryland “have a moment” in the midst of the astrophage near Adrian, I am very sorry. You should definitely watch the movie again.
Everything happens faster.
In the book, Grace and Rocky are together for months, and Grace’s aborted trip home runs about four months before he turns around. The film compresses all of it. Necessary, probably. But the book’s version of that friendship is long enough to grow roots, while the movie’s is long enough to grow a montage.
3. Plot and timeline
The wake-up act is truncated.
The book spends real time on Grace’s adjustment to the ship. He’s (less) depressed. He does trial-and-error science that makes hard sci-fi readers obsess over the book from page one. This introduction to the narrative leans into the problem-solving that makes book Grace such a nerd, and it leaves a lot of the emotional drag for the end of the novel.
The film gets him moving quickly. Within a few minutes, he’s made his way out of the sleeping bay (remembering his name no longer required) and where he can see out of the window of the ship (which doesn’t exist at all in the book, by the way).
The astrophage is more visible.
More of it, more often, much more cinematic. Fair: A microbe eating the sun is a hard thing to film at scale. (This annoyed me to no end, because the book did rely on the weirdness of the invisible astrophage for a few plot points, but again I can’t blame anyone for this interpretation.)
The Earth-side engineering is gone.
No sinking Antarctica with nukes to force CO2 into the atmosphere. No paving the Sahara. No Robert Redell, and no springing him from prison to do it. The book’s whole “how far will humanity go” B-plot is basically a deleted scene.
All four of us found this to be hard to swallow. That’s why we’re still really hoping for that 3-hour-45-minute cut that has yet to see the light of day. (To every filmmaker who forced them to shorten the movie: You are on our poo-poo list.)
The science got montaged.
Many of Grace’s discoveries are shortened or cut, including the multiple taumoeba escapes (which, book readers know, are some of the tensest pages Andy Weir has ever written).
Rocky’s rescue is simpler, but the payoff is a distinct improvement.
Book Grace nearly wrecks everything trying to save Rocky while he’s “out.” Movie Grace puts heat lamps on him and waits.
Losing some of the stress of that moment did not make the theatre any less graveyard-silent, in our experience. Plus, adding Rocky’s sacrificial gift of fuel (there’s plenty on his ship in the book; it doesn’t change his return journey plans at all) was one of the most sweetly tender film moments any of us have seen.
And the PAYOFF?! Seeing Rocky’s ship was a tear-jerking moment, and using that as the exact time to reveal Grace’s cowardice was freaking heartbreaking.
Stratt has a redemption arc voyage.
The film gives her a final scene the book never wrote: on a ship pushing through ice, with some of the data Grace sent back in the beetles, and a tattoo. A V with a line through it, which means “I’ve been in French prison for life.”
That detail came from Weir himself. Co-director Chris Miller explained it in an interview with /Film: Weir figured Stratt went to prison without parole, broke out using her connections, and is out there on the lam, still trying to save the world. The book ends with Grace. The movie ends with her. I have feelings about this, and they are all positive.
So… is the book better?
Listen, I named this podcast how I did for a reason. But! This one was closer than usual — 94% on Rotten Tomatoes, an $80.5 million opening weekend, and a Rocky who works on screen when he had every right to be a disaster. The four of us went in braced and came out arguing about margins, not verdicts.
(I have literally never sat that long without shifting in my seat or taking a bathroom break. IMAX was worth the four-hour drive.)
The full argument (including the fun-fact round where we each had to defend why this is our favorite book and film, or explain ourselves) is in the full episode:
Quick facts
- Book: May 4, 2021 · 4.51/5 on Goodreads (1.3M ratings)
- Movie: March 20, 2026 (US) · PG-13 · Rotten Tomatoes 94%, IMDb 8.5
- Opening weekend (US): $80.5M — crossed $100M domestic in six days
- Filmed at Shepperton Studios, UK; location work at South Parade Pier (Portsmouth) and the Mullard Radio Astronomy Observatory (Cambridge)
- Trivia: this is Sandra Hüller’s first American film. And planet Adrian shares a name with Rocky Balboa’s better half, which we choose to believe is not a coincidence, because the alien is named Rocky. “Yo, Adrian.”
- More Andy Weir on the show: we covered The Martian back in season one — and yes, we compared the potatoes.
We’re The Book Is Better Podcast — a family of four comparing book-to-film adaptations, one argument at a time. New episodes every other Thursday. Find us wherever you listen, or come argue with us on Discord.