How Scientifically Accurate is The Martian?
- 24th Jun 2025
- Author: Alex Thompson
Sci-fact or sci-fiction?
For the second part of our series looking at the scientific accuracy of Hollywood blockbusters, we visit Ridley Scott’s 2015 hit The Martian, starring Matt Damon as stranded Mars astronaut Mark Watney. It is based on the same-titled novel by Andy Weir.
Given Weir family’s scientific background (his father was a particle physicist), it should be no surprise that the author thoroughly thought about the complexities of a future mission to the Red Planet, as well as how one would deal with being stranded alone on an alien world.
Did this attention to detail translate to its success as a big screen adaptation? What does the film get right, and where are scientific liberties taken? And if you want to find out about how realistic your other favourite sci-fi movies are, check out our analysis of the 2013 hit ‘Gravity’.
What it Got Right
Thankfully, for the most part, the film stays true to the book, keeping the science and lateral thinking that Weir so diligently researched. And in some instances the movie even improves on this.
The habitat that Watney creates for himself isn’t described in great detail in the novel, but on the screen what we see is a pretty fair crack at what it would most likely look like. Some of the ideas, such as turning Mars’ atmosphere of carbon dioxide into breathable oxygen, have clearly been created with help from experts to get the most realistic representation.
In fact, an experiment to extract oxygen from the carbon dioxide in the Martian air called MOXIE (Mars OXygen In-situ resource utilisation Experiment) launched on the Perseverance rover in 2020 - years after the film's release. And in its first year of operation on the red planet, demonstrated it was possible.
The idea that food could be grown from the Martian soil is credible in the science community, and if Watney chooses a location where the soil is slightly acidic then his decision to grow potatoes here is a smart one.
We see our protagonist jumping around Mars with an extra spring in his step. Considering he has been abandoned by his team, it’s unlikely its due to his mood and more about the planet only having 38% of the gravity we’re used to here on Earth. This is also very useful for when Watney has to move around some pretty heavy equipment, as it would only weigh a little over a third of what it would on our planet. That he sweats as much as he does in his multi-layer EVA suit is also correct, as are other parts of the film when he’s cold due to the quickly dissipating heat in Mars’ chillier environment.
The timings in the film are also pretty accurate. Assuming Earth and Mars are at one of their closer points to one another, its estimated that current technology would get us there in six to nine months, lining up with how long the crew take on their journeys. When Watney is communicating with Earth, he has to do dig up NASA’s Pathfinder (a real spacecraft I might add) and communicate with NASA via techniques such as ‘Yes/No’ questions and placing alphabetical stones in a circle that Pathfinder could look at. This is in likelihood the best way of doing this – due to the distance between planets, a one-way message would take between three and twenty-two minutes to reach its destination, meaning waiting for a response could mean a wait of up to three quarters of an hour. Therefore verbal communication is impractical and NASA being able to spell out its answer using the Pathfinder’s camera is a pretty ingenious way of getting around the issue.
The ’slingshot’ gravity-assist method is also the correct the way of returning the crew back to Mars, using the Earth’s movement and gravity to ‘power-up’ the spacecraft before launching it back into space (there is a part of this scene, however, that will be addressed in the next section….) And yes, the dramatic finale where Watney launches himself through the atmosphere to be caught by his team is for the most part possible, although in no way am I saying that the plan working could be considered ‘likely’.
What it Got Wrong
Okay, let’s get the big one out the way with….. the storm that knocks down Mark Watney, setting off the chain of events that form the rest of the film, is impossible. Whilst winds on Mars can reach up to 100 kilometres per hour (and ruin a lot of expensive science equipment by blowing dust everywhere), the lack of atmosphere means the winds wouldn’t feel much stronger than blowing on your hand. Weir himself has acknowledged this in interviews, admitting he knew it couldn’t happen but “I needed (Watney) knocked down.” The bad news is it means an absolute fundamental part of the plot is unrealistic, the good news is this pretty much is the only thing in the film which is outright impossible.
Realism could still be improved upon though. The issue with radiation is never fully addressed, as astronauts spending this long on the Red Planet would certainly need some assistance combating this. There are certainly ways to protect the crew to an extent, a few sheets of plastic for the weaker stuff and potentially a cabin made of metal or water for the more potent, but this is where setting the story in the future has its advantages. “I just said in the intervening time they’d invented some kind of material that take cares of it,” said Weir.
Watney decides to source water for himself by splitting the rocket fuel into nitrogen and hydrogen, then combining the hydrogen with oxygen to create H2O. Whilst this is an entirely possible way to create water, it would be a lot easier to source it from the soil. It would take far less time and effort and stops Watney from using precious rocket fuel which might be his ticket off the planet (even if he probably acknowledged this was unlikely at this stage in the movie).
On Earth, pivotal scenes take place at the Johnson Space Center and the Jet Propulsion Lab (JPL) as scientists look for a way to save Mark. These are real places, however they are nowhere near as glamourous as they look in the film. Even in the near-ish future when the story is set, so much funding being put in to creating buildings that look like these is pretty unfeasible. The same could be said for the spaceship the crew is on – why would they create such a logistical and financial burden for themselves when a much simpler craft would be much more efficient.
And the ‘slingshot’ meeting scene? This method has been used since the first crewed Apollo missions. That only one scientist only thought of it this far into the problem, and must explain it to the heads of NASA like it’s a revolutionary concept, begs the question how everyone in that room got their jobs. Yes of course the scene exists to explain to the moviegoers how it’s going to work, but nonetheless the fact NASA administrators didn’t think of the most obvious solution probably explains how an agency mission could leave an astronaut on Mars in the first place.
There are a few more pedantic questions when you really think about it. Why were they storing so much poo? Did Nasa really need every waste disposal they ever made to be brought back home for research? And why was one member of the crew waving a resupply mission onto Mars like an airport runway worker when the spacecraft was uncrewed? These are the things that keep me up at night….
Conclusion
NASA once ranked The Martian as the most realistic space film of all time. Pretty high praise indeed. Whilst I can’t give it perfect marks as the premise of the whole plot is based on a lie, it’s otherwise as realistic as a sci-fi can be.
Space Realism Rating: 9/10
Full references/credits:
(Banner) How accurate is The Martian? Credit: National Space Centre
(1) Matt Damon making cement hand prints on his visit to the Mars yard of NASA's Jet Propulsion Laboratory. Credit: NASA/Bill Ingalls
(2) Matt Damon's EVA spacesuit is on display at The National Space Centre. Credit: National Space Centre
(3a) Martian dust storms wouldn't be as strong as shown in the film. Credit: NASA
(3b) NASA's Johnson Space Center looks nice, but not as nice as in the movie. Credit: NASA
(4) This graphic for ESA's Exomars Rover shows The Martian got several pieces of key science correct. Credit: ESA
