In the Guardians of the Galaxy film, people repeatedly jump into space and float around a bit, for giggles. Why's this okay, and they don't, you know, die immediately?

I vaguely remember a line similar to

Her mods will keep her alive for a few minutes, but after that....

So space is clearly dangerous [citation needed]. However, civilization has found some ways to reduce the risk through body modifications, but I got the impression that Quill didn't have those mods. Nevertheless, he's still pretty okay with being in space, even for extended periods when he has his mask on. Space is cold [citation needed], and I imagine that your fingers would get a bit chilly after a little while with no suit on.

So; what gives?

  • 5
    We have no idea what Quill's clothes are made from. Could be space-proof.
    – Daft
    Apr 22, 2015 at 13:27
  • 5
    We do know that Quill has had at least a translator implant installed in his neck. Add to that, the fact that he's not entirely human, and we don't know exactly what his physiology is, or what else he may have had modified.
    – phantom42
    Apr 22, 2015 at 13:36
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    I don't have an in-universe answer, but in reality cold wouldn't be an immediate problem, since the vacuum is a great insulator that slows heat transfer (a thermos uses a layer of vacuum for just this purpose, see here). The main problems have to do with the lack of pressure, which according to this article on vacuum exposure means that "the gas exchange of the lungs works in reverse, dumping oxygen out of the blood" (along with other less immediately fatal problems like 'the bends').
    – Hypnosifl
    Apr 22, 2015 at 13:38
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    Space being "cold" is not the same as some gas or liquid around you being "cold", because space is empty. Compare walking into a sauna with 90 degrees Celsius air temperature, and jumping into a body of water heated to the same temperature. (Ninja'd by Hypnosifl.)
    – DevSolar
    Apr 22, 2015 at 13:39
  • 3
    It's worth noting that without his mask, he DID get pretty messed up, pretty fast. That scene only lasts 20-30 seconds, and by the end his skin is frosting, his eyes are bleeding, etc. With his mask he lasts longer, but the flight from the Kyln to his ship is, again, only a few seconds long. Being unprotected in space is possible in Guardians (as in real life), but not for very long.
    – Nerrolken
    Apr 22, 2015 at 22:12

5 Answers 5


OK, enough with the comments, let's forge an answer. ;-)

Quill's nature and equipment left aside, the vacuum of space is not as immediately lethal as you might expect.

  1. You will not "explode". However, you will experience (severe) swelling.

  2. You will not be shock-frosted, like you would when diving into a pool of liquid nitrogen. The vacuum itself acts as an insulator. Quote comment, "compare walking into a sauna with 90 degrees Celsius air temperature, and jumping into a body of water heated to the same temperature." Or walking in freezing air vs. being submerged in freezing water, as Random832 commented.

  3. You will not be insta-fried by radiation, unless you're close to a star or in an intense magnetic / radiation field. (Or astronauts would be in real trouble, since they're above the ozone layer all the time.)

Comments keep coming in on 2. and 3. above. So to clarify: Yes, you would eventually get problems with temperature (in one way or the other, the judges are still out on this one) and radiation. However, by that time you're already dead, see below.

The things that are a problem:

  • Swelling, circulatory failure, paralysis, ebullism.

  • Rapid evaporation of moisture and associated cooling, up to and including formation of ice in the respiratory tract.

  • Rapid loss of oxygen from the blood stream.

  • Collapse of the lungs.

  • Danger of lung rupture if holding your breath.

Wikipedia has an article on it: Space exposure.

Again, to clarify: You hold your breath, your lungs rupture and you're dead. You exhale, you lose oxygen from your blood rapidly, fall unconscious within about 15 seconds, and die within two, three minutes at the most.

Given that Knowhere is a structure that wouldn't hold an atmosphere by means of natural gravitation to begin with, and is stated to be "hidden between the dimensions", we could -- with just a little bit of handwaving -- claim that there is some (artificial / inter-dimensional) atmosphere even out to the point where Quill and Gamora are floating, reducing the aforementioned effects to the point where Quill's quite short EVA becomes survivable.

(Real-life astronauts go on EVA's with their suits at as little as 30% of cabin pressure, with no adverse effects. They do so because a suit that's inflated like a balloon doesn't allow for easy movement.)

  • I am not so sure of your "insta-fried" point. Astronauts always have radiation protection and shielding. (Even then a 6-month stint on the ISS can accrue a dose at the 50mS maximum for a yearly dose for radiation workers.) And Van Allen belts trap radiation: Jupiter's Van Allen belt is possibly twice as wide as the planet itself and is one of the harshest radiation areas in our solar system. ( en.wikipedia.org/wiki/Magnetosphere_of_Jupiter )
    – Yorik
    Apr 22, 2015 at 15:14
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    @Yorik: Wikipedia says "Estimates are that humans unshielded in interplanetary space would receive annually roughly 400 to 900 mSv". According to one simple model, radiation increases cancer risk at a rate of 5.5% per Sv. So five minutes unshielded in space would result in a 0.000047% chance of contracting cancer. Probably not OSHA compliant, but hardly "insta-fried". Apr 22, 2015 at 15:50
  • @NateEldredge: the apollo mission experienced a calculated 13 rads in a 15 minute transit of the van allen belt. Shielded, the astronauts received about 1 rad (300 being lethal, and also the max career dose). The Jupiter van allen belt is over 1000 times as strong. It also sterilizes several of its moons' surfaces. So, it has a lot to do with the neighborhood.
    – Yorik
    Apr 22, 2015 at 16:00
  • I just think the handwave with the "unless close to magnetic field" is a little strong: the majority of humanity in space would potentially be close to a planetary magnetosphere.
    – Yorik
    Apr 22, 2015 at 16:05
  • 1
    @Sahuagin: It's not that there's no convection, but that there's no conduction. (It's also true that there's no convection, but that's not why vacuum is insulating. Mere lack of convection would mean that you'd lose heat to the immediately surrounding vacuum until its temperature rose to being in equilibrium with you.)
    – ruakh
    Apr 23, 2015 at 1:53

His armor allows him survive absolute zero :

The Star-Lord Armor allows the wearer to survive in the absolute zero, Vaccum of space. The suit is able to travel through space under it's own power. The suit provides the wearer a personal energy shield for protection.

Granted it looks quite different to how he looks in the movie. And it could be argued that in the movie, he's only wearing a trench coat and trousers...

As DevSolar points out in the comments:

It could also be argued that the space around the mine -- which itself is a mostly hollow structure that is unlikely to hold an atmosphere by natural gravity alone -- isn't a complete vacuum. The "condensation" effect on skin and clothing would also be explainable in a hand-wavey fashion by there being "a little" atmosphere around.

We don't really know the conditions Quill was in, or really enough about Quill himsef to know what he could / could not handle.

  • 1
    It could also be argued that the space around the mine -- which itself is a mostly hollow structure that is unlikely to hold an atmosphere by natural gravity alone -- isn't a complete vacuum. The "condensation" effect on skin and clothing would also be explainable in a hand-wavey fashion by there being "a little" atmosphere around. At least that was my take when I watched the movie.
    – DevSolar
    Apr 22, 2015 at 13:42
  • 4
    I don't think the temperature of space is absolute zero.
    – Clyde
    Apr 22, 2015 at 13:54
  • 2
    @Clyde well then you had best get in touch with wikia.com and let them know.
    – Daft
    Apr 22, 2015 at 13:56
  • @DevSolar yep, a valid point as well! Into my answer you go!
    – Daft
    Apr 22, 2015 at 13:59
  • 1
    @clyde: you are correct in a sense. In an absolute vacuum, there is no temperature. But in space, you will definitely experience temperature via interaction with radiation. When a person is doing a spacewalk around the ISS, they can experience front to back differentials as high as 275F. nasa.gov/pdf/379068main_Temperature_of_Space.pdf High energy particle strikes can also be measured at extreme temperatures, but they are so infrequent that the heat re-radiates before a net positive change occurs.
    – Yorik
    Apr 22, 2015 at 14:36

Space will not kill you immediately. You will most likely die of oxygen depletion and begin to suffocate. Your body will not explode like most people want you to believe.

A few downsides to space.

  • No Oxygen - You will choke to death, so basically as long as you can hold your breath is how long you got. This will be what kills people most of the time.
  • No Ozone layer to keep radiation from making contact with your skin - will slowly kill your cells from exposure to gamma radiation, unless you're behind planet or moon.
  • Don't have exacts on this statement, but space is very cold. So freezing to death is probably another way to go if left out to long.

Your skin will probably turn red though from your insides trying push out and creating pressure, but your skin and skeleton are more than enough to hold your organs and the rest of your insides...well inside.

Edit: So I think he has till he runs out of oxygen, plus about another 2-3 minutes before his brain suffers severe damage, I think the time you have before severe damage is around 4 minutes after your oxygen levels have been depleted.

  • 3
    Related link to decompression myths -- Space exposure. The latter makes the depiction of Quill's EVA look downright realistic. ;-)
    – DevSolar
    Apr 22, 2015 at 13:57
  • 1
    unless you're behind planet or moon. Or, you know, wearing a super awesome space suit like Quill. Radiation is not an issue here.
    – Mast
    Apr 22, 2015 at 15:05
  • @Mast Totally possible, I was just listing things that could go wrong. Was he wearing a space suit or his normal clothes in that scene? Either way the radiation was not going to kill him in the short amount of time he was exposed.
    – Clyde
    Apr 22, 2015 at 15:11

You may want to read this What would really happen if you were exposed to space question.

Of course you need to modify this to account for the (fictional) tech used in the Guardians of the Galaxy movie.

As other's stated, Quill's equipment helps somewhat but the real world effects of exposure to a vacuum would be different than the results portrayed - even if Quill's equipment worked as advertised.

My advice on this issue is that Guardians of the Galaxy effects are powered by plot (TM) and don't need to/won't make physical sense.


First, you have some misconceptions about what exposure to space is like.


Many works of fiction show or describe the effects of exposure to the vacuum of outer space in unrealistic ways, such as showing the victim exploding.

Second, it's reasonable that Knowhere has a limited atmosphere surrounding it, which lessens the effects of space exposure to an extent where Quill could have survived for a number of seconds and recovered quickly thereafter.

This is supported by the presence of sound, which requires a phyiscal medium to travel through. (Or maybe this was added for the audience's benefit, since it's a movie...but I don't think you prefer "it's a movie" explanations.)

You might ask how the atmosphere remains there, rather than dissipating. But understand that these are the same folks who can control gravity. If you can control gravity, containing a (weak) atmosphere is possible.

  • I felt like the sound was us hearing their radio communication, but yeah, I'm realising that I didn't know much about space exposure. However, I still wouldn't recommend it.
    – Yann
    Apr 22, 2015 at 20:59
  • @Yann, I believe you hear the sounds of the flying ships, and explosions. Apr 22, 2015 at 21:23

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