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These were a group of some of the brightest scientists in the world, right? So why would they decide to take off their helmets on an alien planet?

Even if things were safe, they would still be unable to board the ship without going through quarantine procedures, so why do it?

To be clear, six characters venture onto the planet:

  • Shaw (archaeologist)
  • Holloway (archaeologist)
  • Fifield (geologist)
  • Millburn (biologist)
  • Ford (doctor)
  • David (android)

ALL of them take off their helmets.

Even if Holloway's scans revealed the Co2 levels were low enough for the air to be breathable, what about airborne diseases? I'm no scientist and I understand the dangers, so why don't they?

Does anyone have an answer?

  • 2
    I thought it ludicrous to remove their helmets in the cave. Only idiots would do that. Coming back from the moon, Armstrong and Aldrin had to spend a week in quarantine. And Shaw telling the security man to not bring any weapons on their first exploration was another ludicrous happening. No weapons? On a strange planet? And these are intelligent people?
    – user28633
    Dec 13, 2015 at 2:06
  • 1
    Given our recent collective education on airborne diseases thanks to COVID, Prometheus is even more absurd :( Jan 15, 2021 at 10:58
  • 1
    Do you all actually think that a society with the capability to master interstellar travel and to explore such planets successfully would not have sensory, sampling and testing technology to detect dangerous airborne diseases or, at the very least, unknown airborne substances? Your understanding of the dangers are based on 20th/21st century technology. Their technology is based on their understanding of the dangers and safeguards built to detect and alert them when that is a possibility. Oct 25, 2021 at 21:22
  • All helmet removals in movies are so you can seen the actors. Nov 8, 2021 at 16:37
  • @blacksmith37 Yes, but the question is "Why did the crew take off their helmets?" not "Why did the ACTORS take off their helmets?" ;) Nov 8, 2021 at 17:22

3 Answers 3


The removal of the helmets isn't some half baked attempt at taking risks, and was an important plot point in the film.

The crew is following the "Pups" deeper into the maze of caves, and they come across running water. It's at this point they realize they are inside an alien terraforming plant, because the outside air is toxic but inside it's clean fresh air. As quoted by one of the crew "cleaner than Earth's actually".

It's Holloway who removes his helmet (as others protest), but he's also the one who wrote the thesis predicting the planet they were on would be occupied by the Engineers. At this stage in the film, the crew is still expecting to discover the Engineers alive and well. Their attitude is positive and they still view the Engineers as friendly beings.

After the crew removes their helmets, the two guys back on the ship settle their bet that the structures were used for terraforming.

It would be difficult to sell the terraforming intention of the Engineers if the air wasn't breathable, and would be difficult to sell that to the audience if they left their helmets on.

The audience can now assume the Engineers are real and that Holloway's thesis was correct to bring them to this planet, but in the very next scene we find out everything went wrong. They watch the holographs run through the hallway and discover the Engineers are dead.

The fact that they now have their helmets off also raises the risk. Had they found breathable air after discovering the holographs, then the direction of the film would be completely different.

I agree it was stupid for them to remove the helmets, but it was also a mistake to go to the planet, enter the structure and open doors. This isn't a crew playing it safe, but one misguided by their own excitement in making a great discovery.

  • 3
    Now that's a good answer! I don't agree with you that it was a "mistake" to go to the planet, or open the doors, though. That's taking it to extremes. You may as well say it was a mistake to get out of bed that morning, or for Shaw to check her emails on the day she got the invite to join the crew. We're not talking about mistakes anyway, we're talking about illogical behaviour, so it's also completely irrelevant. Nov 24, 2012 at 13:53

I agree the helmet removal was preposterous... hard to believe anyone would take that risk, given the stakes.

But think of it from a film-making perspective... if the characters don't remove their helmets, their heads and faces are largely obscured through much of the action of the movie, which would probably have been less visually compelling than when they're helmetless.

So, like a few other "mysteries" in Prometheus, I think the answer to this question involves film-making logisitics: the removal of helmets was likely inserted into the screenplay to allow the actors to be seen without their helmets.

  • That definitely crossed my mind, but you'd think someone from the film would come out and say that. Also the helmets were complete domes of glass, with full visibility. I wonder if it was more to do reflections on the glass? Nov 20, 2012 at 19:23
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    I'm not gonna downvote as you do have a point but I generally don't like this kind of explanation as you can reduce anything to it: Why did they go to the planet? Because it would be a boring movie if they didn't. Why were the engineers agressive? Because it gives more action on screen. Just my 2 cents
    – Origin
    Nov 21, 2012 at 7:51
  • 1
    I agree it's more satisfying to have an in-movie answer. But movie content is frequently impacted by logistical concerns. For example, on director's commentaries on DVDs, you'll often hear "we wanted to do X but couldn't because of Y."
    – Shiz Z.
    Nov 21, 2012 at 18:54
  • @Origin You're talking about drama, Shane is talking about logistics. Nov 24, 2012 at 13:47
  • I agree with this. It is needed for the film, and so lazy writing and idiot balls provide the excuse to get them to do it.
    – DaleyPaley
    Aug 27, 2013 at 7:14

Their scans indicated it was safe to breathe. As scientists, they constantly formulate hypotheses and test them, according to the scientific method. If all their tests indicated it was safe, the next step would be trials using living organisms. They could have used some other animals (if they had some) but I believe they were rather impressed by the whole meeting-our-makers-thing that they were very optimistic. They were also only archeologists, more trained in history and excavations, then in biology (and hence don't focus on the toxic gasses).

The thrill of breathing the air might be enough for them to go through quarantaine (would you pass up that chance because you don't want to go through quarantaine?). It's a discovery of a lifetime... Most reactions on "taking their helmet off" seem to forget this typical human behaviour. They've come all the way from earth in stasis, they're not turning back now. Don't forget that they might not be the brightest scientists as they're pursuing their own hypothesis. There was no selection protocol with ample (qualified) candidates for the job. Other scientists might be more careful.

  • 2
    A biologist and a doctor also took off their helmets. And I'M no scientist but I understand about the existence of airborne illnesses! Nov 19, 2012 at 8:26
  • I am totally agree with @origin s answer. The reaction of the discovery made them forget about their typical human behavior momentarily. The situation is something that should be felt, rather than logical reasoning. These moments are judged by emotions only.
    – Mistu4u
    Nov 19, 2012 at 8:35
  • @DrThaddeusVenture - true, but didn't they take them off after the archeologists (so they saw it wasn't instant death)? Again, the excitement could have gotten the better of them. Another motivation might have been their belief/faith in the engineers. The engineers would have made sure they could survive (or could even save them if they did got ill).
    – Origin
    Nov 19, 2012 at 8:43
  • In fact remember what Holloway concluded( rather believed) They were terraforming.
    – Mistu4u
    Nov 19, 2012 at 8:45
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    They could be optimistic and plan to remove the airborne diseases with their (advanced) medical equipment if they happen to contract one. The scene in the med bay shows that they are well equipped. As you say, it's a common question on this movie with lots of debate, which in itself proves the difficulty to provide 1 solid answer.
    – Origin
    Nov 19, 2012 at 11:12

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