Can Nuclear Weapons Kill Xenomorphs?
May 28, 2014 8:04 PM   Subscribe

Can Nuclear Weapons Actually Kill Xenomorphs? Is it, in fact, the only way to be sure? It seems like they can handle a lot of physical battering, which makes me wonder if nuking the site from orbit in Aliens would ACTUALLY have killed them. If you are answering this question, please support any assertions by citing some part of the Alien canon; I have no use for whimsical uninformed opinions here; I'm a very busy person.
posted by Greg Nog to Media & Arts (29 answers total) 18 users marked this as a favorite
They can handle "A lot" of battering but a nuke goes beyond "a lot." Consider that (lots of) small arms fire can kill them; a nuclear explosion brings with it far more pressure than bullets or grenades and far more heat than a flamethrower.

Now, if you want to talk radiation - that's another matter; xenomorphs may in fact be able to live in deadly-to-humans radioactive wastelands without being much bothered. But nukes are in fact Very Large Bombs and kill via basically up-scaled versions of the same physical processes that we've seen kill xenomorphs on a smaller scale.
posted by Tomorrowful at 8:09 PM on May 28, 2014 [6 favorites]

They would have to retain their level of material differentiation at several hundred million degrees in order to survive, right? So they would be plasmas of some kind, I guess? And then they turn back into the facey guys and the head monsters?
posted by clockzero at 8:11 PM on May 28, 2014

Nuclear weapons can not only vaporise matter at ground zero, but also disintegrate the very atoms it's composed, yes, you can be sure it kills bugs dead.
posted by sexyrobot at 8:11 PM on May 28, 2014 [2 favorites]

In Alien 3 the xenonorph was killed from thermal shock when water hit molten lead. The blast pressure alone (i.e. not even counting temperature) of a single nuclear bomb can hit ~50psi/1000mph. As everyone in the surrounding area didn't encounter a blast wave remotely like that, the force causing the xenomorph to explode is most likely less than that.
posted by griphus at 8:19 PM on May 28, 2014 [1 favorite]

Can Nuclear Weapons Actually Kill Xenomorphs? Is it, in fact, the only way to be sure?

I think it's pretty clear that when they said that line they had a lot less information available than we do, and nothing really can be read into the line itself.

The fact that they can be harmed or killed by small weapons means they are not immune to the mechanical damage from the explosion, and we have to assume there is SOME limit to how much heat they can withstand. So it's just a question of how many nukes you have and how near you can get them to the aliens. But to me, it seems unlikely that there weren't Xenomorphs in many locations around the planet both above and below ground. I don't think there's any reasonable way they could be carrying enough nukes to completely sterilize an entire planet - if they could do that would they need to collect xenomorphs for their secret weapons program? And they clearly don't have the sensor tech to find/target xenomorphs at a distance.

"Knowing for sure" is not an objective they could ever have accomplished.
posted by aubilenon at 8:22 PM on May 28, 2014 [3 favorites]

It seems like they can handle a lot of physical battering, which makes me wonder if nuking the site from orbit in Aliens would ACTUALLY have killed them.

It would have absolutely vaporized any within the immediate range of the blast, but I'm fairly sure that most of the ones underground or in hardened buildings would have survived.
posted by empath at 8:22 PM on May 28, 2014 [1 favorite]

However, xenomorphs are resilient enough that nuking the site from orbit doesn't guarantee anything save for the death of any xenomorph in the blast radius. Even if then planet is literally blown up, like Alderaan, a particular xenomorph may have a way to survive the depths of space as they inherit biological advantages from their host.
posted by griphus at 8:22 PM on May 28, 2014 [1 favorite]

They're tough, and resistant to heat, radiation and pressure changes, but not invulnerable. There'd be significant overpressure, and mechanical damage from debris would fuck a xeno up.

The real issue isn't whether nukes would kill 'em, it's whether nukes would kill all of 'em, and that is far from a sure thing. Eggs and shit, maybe one is taking a dump a mile underground, even one escapes nuclear justice and they could pop up again anytime.
posted by Sternmeyer at 8:24 PM on May 28, 2014 [1 favorite]

Nuclear weapons can not only vaporise matter at ground zero, but also disintegrate the very atoms it's composed, yes, you can be sure it kills bugs dead.

If a nuclear weapon caused atoms to disintegrate, does that mean they'd convert into energy suddenly like radioactive matter does a little bit at a time?
posted by clockzero at 8:24 PM on May 28, 2014

There were human beings who survived the Hiroshima explosion and then succumbed to burns and radiation afterwards-- i imagine that xenomorphs would be able to shrug those sorts of injuries off.
posted by empath at 8:25 PM on May 28, 2014 [4 favorites]

If you're curious about nuclear weapons effects, I highly recommend Alex Wellerstein's NUKEMAP. It's pretty safe to assume that anything plausibly biological is not going to survive within the fireball of a nuke (the orange circle on NUKEMAP). If the temperatures of thousands of degrees don't get you, the overpressures in the 100s of PSI will. (For reference, 20 PSI is enough to knock down all but the most seriously reinforced buildings and kill almost 100% of people).

Distance matters a lot here. If you presume that all the Xenomorphs are concentrated within a half mile radius, one modestly sized nuke (of the sort currently sitting on top of US Minuteman missiles) could plausibly take them all out, as long as none of them are buried more than a couple thousand feet underground. Even if they're confined to a complex several miles in size, with the right combination of more/bigger nukes, you could plausibly get them all. But once their geographic dispersal gets an order of magnitude beyond that you start needing weapons that are implausibly large and/or implausibly numerous.

But ultimately there really is no way to be sure that you've killed all of the Xenomorphs, especially if they're buried underground. Blast effects are weird and hard to predict. One of the reasons that the Manhattan Project scientists were caught off-guard with how deadly the radiation from the bombs dropped on Hiroshima and Nagasaki was because their calculations suggested that anyone close enough to be bothered by the prompt radiation from the bomb would almost certainly be killed outright by the heat and blast effects. And yet many people survived those effects to die of radiation sickness. If you're nuking a city, you can consider it mission accomplished if you kill or maim most of the population. If you're nuking a missile silo you don't care if every last missileer is dead as long as that missile isn't going anywhere. If you're nuking xenomorphs, you need to be sure that there isn't an egg buried in some geological anomaly that protected it from the blast. And barring technology at a level much greater than anything we've seen in the Alien canon, that's just not plausible.
posted by firechicago at 8:46 PM on May 28, 2014 [5 favorites]

"Look, this whole station is basically a big fusion reactor..."
posted by Mister Moofoo at 8:49 PM on May 28, 2014 [2 favorites]

HOW can you even ask this???

Did you not OBSERVE Corporal Hicks insert the barrel of a shotgun into the mouthal orifice of a xenomorph, offer the suggestion "eat this," and subsequently discharge the weapon, thereby terminating said xenomorph???

If you could dispatch one with a shotgun, don't you think nuclear weapons would have provided the necessary certainty?
posted by eeby at 8:58 PM on May 28, 2014 [5 favorites]

Please, whatever you answer, please cite a source for your assertion based on some piece of the Alien franchise -- either a movie or even one of the extended universe comics/novels/etc.
posted by Greg Nog at 9:00 PM on May 28, 2014 [3 favorites]

Aliens was basically the Vietnam War in Space. From that perspective, nuclear weapons would end up being ineffective. Yes, xenomorphs are not invincible and would probably die from a nuke, but ultimately that doesn't matter. Ho Chi Minh himself said, "You can kill ten of our men for every one we kill of yours. But even at those odds, you will lose and we will win."
posted by FJT at 10:07 PM on May 28, 2014

I think you need too look at what happens to the alien at the end of Alien, as well, when it gets bounced into the Narcissus's booster. Vaporized and nicely dead. The nukes are going to bring that to all of LV-426 and all the bugs on it.
posted by Admiral Haddock at 2:29 AM on May 29, 2014

(Disclaimer: no single canon source; extrapolation from observed behavior and biology in Alien and Aliens.)

Braconid wasps are ancient parasites. The larvae employ some unusual genetic tricks to grow undetected inside moth caterpillars until they erupt in their maturity, usually killing their host.

A genus of Braconidae is the reigning animal champion of radiation survival. 1000 rads of x-ray exposure suffices to kill a human; a cockroach can endure up to ten times that dose. Habrobracon larvae will not die short of 180,000 rads.

If we assume a degree of convergent evolution for the vaguely insectoid endoparasite under consideration, we could say that larval xenomorphs outside of, or sheltered from, the main blast of a nuke would stand a high chance of surviving the initial radiation flash and subsequent fallout. The only way to be sure, then, is to catch everything in the main blast. A planet-buster would not be out of order.
posted by Iridic at 2:43 AM on May 29, 2014 [3 favorites]

Not all the xenomorphs would be killed, because it's scarier if there's at least one left over to unexpectedly attack and terrorize the humans who will eventually come poking around, so there will always be at least one left, QED.[1][2][3][4]

[1] Alien
[2] Aliens
[3] Alien3
[4] Alien: Resurrection
posted by Drexen at 2:45 AM on May 29, 2014 [16 favorites]

Xenomorphs are not particularly resilient to physical damage - in Aliens and the Aliens vs Predator games, they are killed by grenades, bullets (even just from pistols), flamethrowers, and with melee weapons of various designs (by Predators). Their strength comes in speed and numbers, and resilience to hostile environments like acid, atmospheres that humans couldn't breath in, and hard vaccuum.

Given that a nuclear weapon exerts magnitudes greater physical force and heat than any of those infantry weapons that have been proven to kill them, yes, nuclear weapons kill xenomorphs.

Is it the only way to be sure? As above, in the context of the film I think the line is assuming
- all the xenomorphs are in the colony
- trying to hunt down and kill the xenomorphs in person may accidentally leave an egg or facehugger alive to spawn more xenomorphs and/or a queen.
Thus - a nuclear weapon that utterly destroys everything within a multi-mile radius (presuming a military spacecraft has nukes at least as big as 100Mt - and they could bombard the planet with multiple warheads to cover a larger area anyway) is the "only way to be sure" that they kill everything in the colony and don't accidentally miss something.
posted by EndsOfInvention at 3:53 AM on May 29, 2014 [3 favorites]

One of the early Dark Horse comic series had more marines return to LV-426 after the site blew itself up and they got their ass kicked too. Many aliens survived.
posted by Che boludo! at 5:42 AM on May 29, 2014 [1 favorite]

One of the early Dark Horse comic series had more marines return to LV-426 after the site blew itself up and they got their ass kicked too. Many aliens survived.

Now that I think of it, that was the case in the game Aliens: Colonial Marines as well. And that was officially canon! So I guess that's pretty definitive.
posted by Drexen at 7:01 AM on May 29, 2014 [1 favorite]

Not to mention the derelict space craft is several miles away from the colony and would almost certainly not have been affected by the blast. There are still thousands of eggs waiting for the curious to wander by and restart the whole cycle.
posted by Eddie Mars at 7:04 AM on May 29, 2014

Given that the flamethrowers in Alien seemed an effective method of killing the xenos, as well as pistols and the aforementioned shotgun, any alien within the blast radius would be killed, I imagine. However, the eggs in the derelict are still there, and if the explosion didn't penetrate the deeper levels, they might have survived.

On the other hand, the nuke option probably represents the biggest fly swatted option they have available. I think at that point, Hudson is no longer willing to try all the steps in between M41A Pulse Rifle and thermonuclear assault from the safety of orbit.
posted by Ghidorah at 7:14 AM on May 29, 2014 [1 favorite]

Then again, you're asking about the soundness of Hudson's military strategy, and this is a man who advocate surrendering command to a small child whom he'd only just met.
posted by Ghidorah at 7:15 AM on May 29, 2014 [7 favorites]

if the video game is canon, a shotgun can kill them, and a nuke>shotgun.
posted by bruce at 8:18 AM on May 29, 2014

Thinking about it some more, I think Ripley cares more about the "from orbit" part than the 'nuking the site" part. The only way to be sure of their own safety is to GTFO.

This says "Despite the [fusion reactor] explosion on the planet, several Xenomorphs had survived in the ruins of Hadley's Hope" which clearly demonstrates that one nuke isn't going to cut it. But once you're safely in orbit, you can throw whatever you've got at them, go back for more bombs and do it again, and finally write NEVER GO HERE EVER EVER EVER on your space maps and cave drawings and everything else you can think of, because you obviously can't be sure.

A simple answer is "no, it doesn't matter what you do the the planet if you can't secure your landing gear when you take off" (source: Aliens)
posted by aubilenon at 10:29 AM on May 29, 2014 [3 favorites]

Nukes will work on individual aliens, but aren't sufficient to remove an infestation. According to this book, Aliens:_Earth_Hive, which I have hazy memories of from 15 years ago, nukes could not destroy the alien infestation on Earth. Neither could land mines, tanks, mechas, marines, etc. etc. You basically have to abandon any place they have gained a foothold.
posted by Balna Watya at 1:51 PM on May 29, 2014

Per the director's cut of Aliens, some strategically-placed sentry guns dispatched a number of xenomorphs even as the total onslaught was sufficient to overwhelm the humans' defenses. Let's assume that a single sentry gun bullet, serendipitously aimed, is sufficient to take down your typical male drone. The sentry gun likely fires large rounds at a high muzzle velocity, so it would be reasonable to assume that the kinetic energy imparted on impact by such a round would match that of the 30-06 in this chart (4.05 kilo-Joules). This is the future, so their workaday nukes are probably totally badass compared to what we have now, and so it's safe to assume that this nuke they've got is on par with hydrogen bombs in terms of their explosive yield. Let's say this weapon they're about to drop is a 15 MT bomb, which is an amount of energy equivalent to 6.27 * 1013 kilo-Joules. Now, in comparing these two energy transfers, what will probably be the most relevant metric is the energy density, expressed in Joules/m3. Let's handwave and say that the volume in question for the bullet is that of the 30-06 round, or 4.4 * 10-6 m3. Let's say the volume in question for the nuclear bomb is that of the fireball created by the Castle Bravo bomb, which was 7 km in diameter, or 1.8 * 1011 m3. This gives us:

4.05 kJ / (4.4 * 10-6 m3) = 9.2 * 105 kJ / m3 for the bullet, and
6.27 * 1013 kJ / (1.8 * 1011 m3) = 348 kJ / m3 for the explosion.

So, completely and utterly ignoring the fact that different forms of energy affect an organism in very different ways depending on its tolerances and also ignoring the fact that I haven't seen the inside of a physics class in eight years I think it's pretty damn well certain that it is not, in fact, the only way to be sure.
posted by invitapriore at 7:50 PM on May 29, 2014 [1 favorite]

I think Ripley cares more about the "from orbit" part than the 'nuking the site" part.

I think she is also concerned, though, about anybody else coming to LV-426 and bringing xenomorphs back to Earth, where she will presumably be happily sitting in a rocking chair and petting Jonesy. Isn't this why she goes to the planet in the first place?
posted by ikahime at 2:11 PM on June 12, 2014

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