The canisters in the cargo hold didn't leak,

I've asked myself the same question. Why were the ones in the 'head room' leaking at all? Maybe they were the same canisters that caused the outbreak in the base to begin with and the black goo can just lay dormant for thousands of years but reacts to movements and sounds so it was awaken when the Prometheus team entered. The canisters on the ship must have been certified leak-proof and the ones in the head room were just rejects.

I have a vibe that the ones in the head room were maturing and "gone bad" while the ones im the cargo hold were mature and far better conditions than in the head room. But to think again there can be ,amy factors why the head canisters leaked while cargos canisters didn't....we will see about it I hope so :-)

Its just one of those inconsistencies, that have no explanation. Which ends up giving us a lot to debate over the subject, maybe they go through some process that seals them better before they are loaded onto the Juggernaut? Maybe they are empty but i doubt that was why would the Engineer set off with a Empty Pay Load! Or it could be simply that for some reason the Head/Ampule Room got cut off for so many years and became sterile that the sudden contamination of the atmosphere inside either from chemicals in the outside air or chemicals released by the breathing of the crew. As the Room was not used to such other chemicals for a long time, maybe the sudden change just caused a reaction, i mean it would be safe to assume that the Mural was not painted so that it could only sustain within that sealed environment surely not. I guess my point is just how if you heat up a glass to a high temperature then leave it to cool down in room temperature the glass would cool down gradually. However if you introduce a hot glass to a very cold temperature i.e stick it in a freezer at -15 then the due to the change in extreams being so high the glass just shatters or cracks. I feel something similar occurred here, i.e the sudden change from the Urns and Murals being in such a sterile and cold environment to the sudden contamination of chemicals and temperatures caused them to break down.

I was assuming the Ampule/Head Room was where the urns got 'loaded' & were then stored in the cargo holds? IMO - The urns in the Ampule/Head room were never stabilized after the 'accident' that may, or may not have occurred & killed all but one Engineer?

Consider this: who's to say they didn't leak? They probably did. That scene was was quite short. I assumed they would leak. Would have made an uber creepy image, but like some other things they may have avoided it because it would be an unnecessary foreshadowing. I get the feeling Fifields transformation may have been changed for similar reasons.

There is no mysterious green stone in the other room... and that all I got right now

I was under the impression that the cargo hold was part of the Juggernaut, and was sealed until David investigated the pup, and opened the door. This has led me to believe that the outbreak had a separate set of events attached to it, than the recorded events on the Juggernaut. As has been mentioned in some recent discussions imo there could be two separate events happened separated by a considerable time scale. So I guess the big question is why were the ampules in the headroom activated upon a change in atmospheric conditions. I think the ones in the cargo room were preserved, unlike the ampule room which may have been contaminated by something other than just an atmospheric change.

The urns in the cargo hold were properly stored and thus stable, there was quite a bit of mist surrounding the entire room thus it appears they are refrigerated. Recall what David does with the urn he steals; he freezes it and places it in a refrigerator, likewise, given all the mist it appears the cargo hold was under temperature controlled conditions. Also, the ampule chamber looked like a chapel, thus the urns there could be centuries old and are simply breaking down. Indeed, some looked brown and rusty. An interesting thought to consider, I recall Ridley in an interview stating that the story behind the Derelict is that it was a brother ship and its cargo 'got out of control' and he never mentions 'eggs', only 'bacterial drums of shit you could drop on a planet'. Thus its entirely conceivable that just like the leaky urns in the ampule chamber, eventually these things change over time into 'eggs or something'. Given the visual parallels between the ampule chamber and the 'egg' silo this is entirely viable.

Many questions and few answers. Cargo hold canisters dry, Big Head Room canisters overflowing with goo after the door is opened. What is the significance of the Green Crystal? LV-223 gives us canisters. LV-426 gives us 'eggs'. What is the difference between the two - different species or different lifecycles of the same or similar species? Has anyone else noticed that when Bob the Engineer awakes, the mask he is wearing looks very similar to the face-huggers on Kane, etc. Coincidence or something else? As Charlie says at one point - "we'll never know".

I thought that maybe the canisters in the head room were designed to leak when the door was breached. With the change in air pressure/temperature it would set them off .Like the egyptians fero tombs, sort of like a booby trap.

I might be clutching at straws, but one possible reason why the urns in the cargo bay did'nt react is because David does'nt breathe air.

I think the room is refrigerated

David may not breathe but the others certainly do (or did). All but Shaw had removed their helmets prior to entering the Bridge Room so perhaps the cargo hold was full of empty canisters waiting to be filled or .....?

The one's in the head room started leaking as a reaction to the presence of other biological entities to which it had an attraction. When the group going to meet the living engineer saw the canisters, it was their first contact with them, so they hadn't started leaking yet.

^ Yeah I think you're right, remember the head room had worms in the soil and those worms mutated into hammerpedes... Worms are hermaphrodites, [i]egg layers[/i] and skin shedders... Larval xenos look like worms...

I am sure Ridley had in a interview confirmed the Derelict was carrying a Cargo of Eggs, and the Space Jockey got infected with a traditional Chest Buster. And he was carrying this cargo to a undisclosed location until he got infected he then knew what was coming and set the Ship down on the nearest baron moon he could find and setting off a SOS> We have to remember the clues in the movie are a lot of times in what the actors say, so for example behind the Xeno/Deacon Mural is another Tomb, or so Holloway said. Well maybe behind that tomb they have Eggs, we just dont know, the Murals do indicate that either 1) The Xeno and Eggs where around before the outbreak and thus before the Urns or... 2) The Mural is some kind of Prophecy. Again i rest by my Warming up a Glass and then placing it when hot into a freezer that would cause it to crack or shatter, compared to leave it to cool down in room temperature with no problems.. That meaning the sudden change in atmosphere and temperature may had caused them to leak. You could see at the beginning of the movie the Goo there was more thick but it started to change and liquify as soon as it was exposed to the planets atmosphere. We can thus maybe assume that the Cargo Hold is kept Sterile and sealed still.

Also, we do not know what David does . He might have just opened the door or the command he executes at the door might be starting set of events or procedures. Either he does it intentionally or trough misunderstanding the dialect it might be that he started the whole thing before they entered.

Applying the 'KISS' principle says that David only opened the cargo bay door - any other actions (intentional or otherwise) weren't explored or explained within the movie so speculation is essentially mental masturbation. What we DO KNOW is that when Shaw comes upon them in the cargo bay they APPEAR to be intact. It may be safe to assume that they were intact when she left although the movie doesn't address this one way or the other.

I agree mental masturbation

[quote]mental masturbation[/quote] Not so much as trying to interpret events showed onscreen with passion and interest. That is, unless you're not a fan of the film and doesn't care one bit.