In Prometheus, why do the engineers pointing the humans to reach LV 223, which was not the engineer's home world?

They actually are pointing to a star system not a planetoid this is made clear in the briefing by Holloway. However it is the reverse Promethean hubris of Elizabeth (lets find our makers) and Weyland's desire to beat morality that overlooks assumes that the big guys were making an invitation, not just showing off and pointing out to ancient man and not so ancient man that this is where we come from. They are ancient astronauts come to kickstart and catalyse our progress and tell those whom sit in wonder that we are far superior and come from the sky's.

At some point they concluded that we had failed and were unworthy, a conclusion that David had come to, and we should be punished. Ironically by then the Engineers had grown hubristic and began to sub create. That sub creation set off the  booby trap, the A L I E N pathogen, led to there Promethean down fall on LV223 and irony of ironies another sub created being brings Armageddon down upon them.

As with Tolkiens mythos the rebellious sub creators create only counterfeits which lack morality and any form of nobility or the capacity to create positive artistic outcomes which is the achievement of the creators this huge galaxy or galaxies rich with positive life affirming potential. Right now David has sunk very low and has managed only to challenge his creators with mindless destructive parasitical creatures. Let us hope within a couple of years someone will emerge to put a stop to this nihilistic vision and leave this quasi Engineer dead the victim of his own creations.     

Plus, maybe it's the opposite of an invitation, more like a "DO NOT GO HERE" warning sign.

If you saw a few signs posted in a few different foreign languages, and they all had a similar map graphic, would you just assume it was an invitation for you? Could be anything.

(WARNING Some Very Minor Spoilers for Covenant may follow)

I consider it a test of sorts. In Alien Covenant there is further emphasis on the Biblical and religious connotations that were in Prometheus with the opening scene revealing David is interested in the music of Richard Wagner and he plays the theme 'Entrance of the Gods into Valhalla' on the piano.

Valhalla is an afterlife in Norse myth which only the chosen may enter. The chosen are selected by Odin himself for their glorious deeds in battle, and in Viking culture most warriors sought death in battle above all else so they could enter Valhalla and dine alongside great heroes and the Gods themselves. My interpretation of the star system containing LV-223 is not an invitation to Paradise it is an invitation to humanity to go to a place where it will be decided whether or not they are worthy to enter Paradise.

The Engineers present on LV-223 were probably originally stationed there to monitor humanity from afar and await their arrival so judgement could be made on whether to allow them entry to the Engineer home world where humans would be allowed to interact with Engineers. Those Engineers however seemed to take it upon themselves to destroy humanity before they could arrive, if we look at the extended scene in which Peter Weyland speaks with the Last Engineer he does not initially attack the humans rather simply studying them. His decision to attack the humans is based on the hostility of Shaw towards himself, the hostility of the humans towards Shaw as well as the physical force used to silence her and then Weyland proclaiming himself to be a God and desiring immortality.

The Last Engineer in that moment realises they must be wiped out primarily because in the millennia that humanity has been around it is still a savage, violent race. Perhaps it may even be that the Engineers fear the humans one day rising up against them and destroying them, Humanity is a dangerous weapon in their eyes and should have been wiped out long before they reached LV-223. We can't know for sure but what is also interesting is the deleted scene in the lifeboat where the Engineer initially discovers Shaw hiding he does not attack her, he studies her and it is only after she strikes him with an axe that he attacks her.

We may not know the motives the Engineers had for desiring the extinction of humanity but it seems to me LV-223 was designed to be a testing ground for species seeded by Engineers and it was there that it would be decided whether the creatures could be allowed to go to Paradise with them and interact more with the Engineer culture perhaps even becoming Engineers fully themselves or at least being allowed to operate in their manner. The other side to this was if they failed to pass the Engineers test and could not enter Paradise then LV-223 was a remote planetoid that would be far enough away that the 'failed' species would not present a direct threat to the Engineers home world or their species.

Essentially they invited the species to an area of neutrality that protected themselves, unfortunately the Engineers posted there fell victim to their own biological weapons and some sort of contagion broke out which is still unknown though Engineer bodies were found by Fifield and Milburn with their chests burst open and then there too is the Engineers decapitated head which exploded because of the black goo that had contaminated it. Because of this outbreak the Engineers may have accelerated their plans and decided to just abort the test for humanity because of the contagion they suffered. When the Prometheus arrived, the Last Engineer conducted his study of the humans and was appalled by their savagery, desire to be worshiped as Gods, desire for immortality and the fact they had created David an android, artificial life. It was this that was threatening to the Engineer and rightly so given what David would go on to do.

It is also interesting to examine the Engineers initial reaction in Covenant when we observe them in the flashback which is that of excitement, is it because they thought humanity was deemed worthy enough to join them on Paradise or was it that they believed that the Last Engineer had successfully destroyed them? We don't know unfortunately.

Wow, I can't believe I never realised this plot hole! I always thought those cave-paintings were terrible anyway.

Thanks for the insight, very interesting, I particular love the idea Derelict426 point out, saying the invitation on LV223 is a "test" for humanity and hence to decide whether human are permitted to go to the paradise. Guess I have to watch those deleted scene of Prometheus to understand more. 

Valhalla

When I became aware that David plays "The entry of the Gods" in the prologue I took that and several other elements of the prologue as a sign post into what was going to be revealed.

Valhalla is the place the Einherjar (notice the echo) are taken after death to prepare for the ultimate sacrifice at Radnarok. Given that one of the substantial themes of Prometheus was sacrifice that suggested that the inhabitants of Paradise were connected to the opening scene of Prometheus in which a perfect acolyte is used as the instrument of the catalyser.     

It is also notable that the window scene looks out on the lake which the teardrop shop passes over on the way to the waterfall implying more connections. 

The Outbreak on LV 223.

In the short "The crossing" it opens with text which includes the line 'after the discovery of a deadly ALIEN pathogen'. This is setting up one of the handful of narrative gifts of Prometheus used in Covenant that the source of the XXX121 is the Alien Pathogen.It underwrites Janeks deduction that the airfield they discovered with bombers  on LV223 was not the Engineers home world but a research establishment to dangerous to have on the homeward. That of course is setting up the final move in the narrative the decision to cross to Paradise by Shaw to find her answers.

General 

Whether we like it or not Wayne Haag, who is responsible for creating many of the Engineer architectural and cultural visuals has said that Covenant will drag Prometheus in its wake provide answers and dispense with the bullshit.

Now that we have seen Covenant we can deduce what those answers are and they are precious few and that many of the propositions set up in Prometheus are considered BS and will disappear from the trajectory of the future movies. Given that not one piece of dialogue in the movie asks the question what or who were these people not even its name other than to deduce who caused Armageddon I think the audacity of Prometheus is now behind us and we will get a by the numbers link with A L I E N. 

So whilst Derelict426's ideas displays a lot of intellectual veracity I very much doubt that whether or not it is the "right" interpretation it will be proved or disproved in future movies.

In future when people discuss how to interpret Prometheus they will always need to remember that what was discussed as follow through by Lindelof and Ridley when they were making Prometheus has in all probability been discarded and its what Scott wanted to salvage that matters now and its very little. 

At least I am hopeful that the book prequel to Covenant due in September and written by ADF called ALIEN Origins will give us the answers to the questions raised in "The Crossing" and make sense of some of the outcomes we are offered in Covenant.   

Deleted Scenes 

As to the deleted scenes as they were not restored to an official version, which they could have been, it is difficult to know whether they were just left out or considered non canon. My interpretation of the two scenes mentioned is very simple, they only increased the Engineers conviction that he should complete the mission that had been interrupted by the outbreak of the pathogen. I interpret the destruction of David after momentary fascination with him to be a clear statement to Weyland here is what I think of you and here is I what I think of your creation. He uses David's remains to put an end to Weyland, perfect symbolism. He came to kill Shaw for retribution and personal revenge - after all they are only mortal.    

I'm inclined to think the Engineers figured Humanity would either never make it to Z II Reticuli, or just never make it as a species thus no harm showing them 'where we come from', as some cave paintings were 80 millenia old or thereabouts?

In my works I address the concepts of creating Lifeforms, what it is to be Human, the Questions of PROMETHEUS, and go as far as I dare with the Engineers.

The people involved have come into the situation with different initial perspectives, and while not Science Specialists, they are very intelligent and conduct themselves as such.

"Wow, I can't believe I never realised this plot hole! I always thought those cave-paintings were terrible anyway."

That is because it ISN'T a plot hole. Just because somebody doesn't pick up on something obvious, it doesn't mean it is anyones fault but their own. They were NOT directed towards a singular planet or planetoid. It does not mention that in the movie anywhere. What it does mention is the system. It is made clear that within that system lies a planet/planetoid that seems like its atmosphere isn't too far off from ours.  So they decide to go there. 

Also, in the extras on the blu-ray, it is implied Weyland already knew about the signal coming from LV-426 and when Shaw approached him about her cave findings, he knew he was onto something and that is why the decision was made to build the ship and go out there.  

Is it possible we are all engineered as "Aliens" as an experiment ? A dangerous experiment just as the xenomorphs ? Just not as acutely deadly ? After all look at our reality. All it took to wipe life off of Earth was to contaminate it with humans. Had it been Xenomorphs, the death of the world would have just been quicker. Maybe we were created by Engineers as a bio weapon. When they saw David, they may have realized just how potentially deadly humans are, that we too had evolved to a point where we could also create, but ultimately are a destructive race.

I Missed this Topic...

The way i looked at the Star Map before Alien Covenant was the Engineers were indicating to the Humans that THIS is WHERE you COME FROM. With LV-223  i saw as a Nursery/Green House a Sandbox.  But this became Perverted at a Latter Date to Experiment on Horrific Life-Forms.

It was NOT a Invitation as i think the Engineers had No Intentions to see us Gain Knowledge to a Technological Level that we Reached in the 20th/21st Century.  When the Outbreak had Occurred i think the Engineers just Abandoned us.... leave us to ROT and Destroy Ourselves but in their Hubris and Naivety they LIKELY had NEVER thought that on our OWN we would be able to Advance to what we had Achieved the Last 200 Years... (Prometheus Time-Line).

In LIGHT of Alien Covenant... then the Engineers could have been Pointing to Planet 4, and again NOT as a Intention of a Invitation.  And as Planet 4 had LIKELY some kind of Technology to keep it HIDDEN then the Prometheus just came to a Near by Star System and Targeted the ONLY kind of World they saw that has the Possibility to Sustain Life (LV-223).

@Tinde

Humans as a Bio-Weapon?  Thats Interesting to say the Least, as we are Very Destructive to our Environment....  IF we had NOT gone to Evolve Past what a Ape is...  Then you can be sure the CLIMATE CHANGE would be NO-WHERE as Bad and the MANY Organisms/Animals that are Endangered or Extinct would be WAY MORE LESS.

So we are Destructive, but as a Bio-Weapon it depends on WHY.... the Engineers could IF they had Conflicts, had Sent Down some Humans with some Weaponry thats more Advanced than the Species the Engineers would like to Eradicate and then Humans would LIKELY go and Destroy/Conquer them....

So thats a Interesting Question/Theory.... i think it Depends... another way to look at it is IF the Engineers had seen the Deacon/Neomorph etc as a Perfect Bio-Weapon and Killing Machine.... well THEY would NEED a HOST.  And if a Deacon/Neomorph like Organism... is more Perfect if it comes from a Humanoid Host like the Engineers....

Then to Create Humans to USE as Hosts for their Bio-Weapon Monster/Killing Machines could MAKE SENSE ;)

" if we look at the extended scene in which Peter Weyland speaks with the Last Engineer he does not initially attack the humans rather simply studying them. His decision to attack the humans is based on the hostility of Shaw towards himself"

Indeed i saw this too.... The Engineer seemed to be Intrigued with Dr Shaw, but after he had Witnessed the Actions and Arrogance of Weyland he had KNOWN that Mankind are STILL a Race who are Greedy/Selfish and ONLY CARE about their OWN Personnel Gain.

When the Engineer had Arrived at the Life-Boat he had seemed Fascinated at the Technology and Especially the Video Screen that was Playing the Violin Girl.   There are a Number of Scenes we have NEVER seen... which Include the Engineer squatting down to Read a Book (The Bible).

All of this Implies the Engineer was some what Fascinated by WHAT we had Achieved since they Abandoned us (after the Outbreak).  But Knowing that we have Advanced to be able to FIND their Worlds and USE their Technology and seeing HOW it was that Weyland put his OWN NEEDS above the Others... then the Engineer saw that Mankind are a THREAT that they FEARED and we are a Destructive, Greedy Race.... and so he had NO CHOICE but to Continue with the Planed Mission to DESTROY US.

But with these Scenes Deleted and Alternative Scenes making the Theatrical Release, and RS was Pleased with this... seems to Indicate they had a CHANGE of Plan to HOW they wanted to Portray the Engineers.

So our Engineers were just ANGRY at us and ANNOYED...

"but it seems to me LV-223 was designed to be a testing ground for species seeded by Engineers and it was there that it would be decided whether the creatures could be allowed to go to Paradise with them"

Again this is HOW i saw LV-223, they are Gardeners of Space and if your a Gardener and you want to Evolve/Hybrid or Create something NEW then you would be Better off to TEST these somewhere before you are PLEASED with the Results and then you go and TAKE them to your Gardens.

I see the Juggernauts as merely a Advanced Version of the Seeding Ships (the Original Idea was NO Pebble Ship but Croissant Shaped Juggernauts) And so when i look at the Engineers on Planet 4, i see them as a Race where its Considered a Great Honor that some would be Chosen to become the Foundation of NEW LIFE....   The Ships come Time to Time to Collect some Engineers and they are Taken Away to be USED in a Ritual to Seed/Evolve Life.

This could Explain the Reaction of the Planet 4 Engineers.... which FITS with the Overall Creation Plot and the Sacrificial Scene and Statues and Especially those that Surround the Hanger.

But RS sees they as Welcoming Back the Military....

Yeah, we've had this topic before.....If the Engineers designed this as a 'test' then it's a really convoluted one!

Those cave paintings could have never been found and then what? 

Better off building large objects on Earth that would stand out for thousands of years and point to the system or  leave long lasting metal plaques all over.

But it's the ancient astronaut theory stuff from the 70's and i'm actually cool with it!

Makes a little more spice then just:

Scientist :"Mr. Weyland deep space probes have found evidence of an alien structure on a moon many light years away"

Peter Weyland "Cool. Lets go visit this site!"

I agree i think the Ancient Astronaut/Creators Plot does OPEN the Franchise to Great Potential.

Ridley Scott has said the Engineers would come back from TIME TO TIME to Evolve us both Genetically and Technologically. The Plot seemed to Indicate that as of 2000+ Years Ago, then a Lot of our Knowledge had been Passed on by the Engineers when they Visited us.....  they likely Influenced/Taught us some of our Construction/Architecture.  But they would likely NOT go and Teach us EVERYTHING so we do-not have a Equal Footing.

We can Ponder as to HOW OFTEN they came back?  And for WHAT other Purposes.

The Story of ENOCH could be something that the Engineers have done with Various Humans over the Years.  I would be SURPRISED if the Earth as of 2000+ Years Ago was the ONLY PLACE in the Galaxy with Humans....

Which is what i would have done with a Prometheus 2... go to a FAR FAR AWAY Place... like 15000 LY or more... a Place with Humans and a Few Engineers but maybe also other Races.... like a Real Paradise... as in the Engineers would Collect and TAKE a Few Hundred of Each Species they Deemed Worthy to go and LIVE with the Engineers.

If we loosely look at Biblical Accounts as Fables Based on Engineer Interaction then People like Jesus and Enoch could have been Granted Access to Engineers Knowledge as the Engineers would take them AWAY for a While.

These CHOSEN beings could ACT as Emissaries for the Engineers.

I think it would've been cool to see a cave painting of a juggernaut with the Engineer near it. Would have been very alieny.

"They arrived in this vessel..."

A lot of Ancient Cave Paintings/Petroglyph seemed to NOT show much about Space Craft but Certainly many had Strange looking beings.  The ALIEN Franchise is a Alternative Universe to our OWN and so you can BEND what we Actually have in History to Match the Engineers.

But YES we could have some Paintings etc that seem to show the Juggernaught Ships.  Or even Reveal the Engineers using like Pyramid Type Ships.