Not really sure that this post really says anything that hasn't already been said before (one of my favourite pastimes) but I got on a roll
Thargoforming?
On the speculation about what the cave from that trailer is, and following on from these comments in the online rags; I'm thinking: Thargoid 'mothership' and that we could perhaps be looking at biological 'repurposing' or conversion of planetary material into a living thing, which then becomes a nursery, and so on. I won't say terraforming because that would only be done by humans, perhaps 'thargoforming' is more accurate - although there's clearly no atmosphere, so whatever changes are being made can be done in hard vacuum.
Anyway, just as with terraforming, logically, not all planets would be suitable (at least I hope not!), and it might be that some elements are essential to enable this process to occur. Now I don't *believe* there is a single exotic element that's common to all barnacle planets, say (but there certainly are 'common' elements in, er, common).
But perhaps not *just* the planets' elements themselves - what about the nearby planetary environment? E.g. Gas giants, or ammonia worlds (our favourites after all, right?)
And, furthermore, the stellar environment? Barnacles - for example - are found in and around nebulae - so perhaps that's key, also? As far as I understand it (paraphrasing from the following links),
reflection nebulae like
the Pleiades are visible purely because the
interstellar dust in them (thought to be 'suspended' in a molecular hydrogen gas cloud in the case of the Pleiades) reflects the light of the nearby stars, e.g. Merope - as opposed to being ionised in the case of an emission nebula. Cosmic dust sounds boring, but it turns out it can actually be quite rich in composition, depending upon what type it is.
According to that reflection nebula link:
Among the microscopic particles responsible for the scattering are carbon compounds (e. g. diamond dust) and compounds of other elements such as iron and nickel.
And it turns out (read the interstellar dust link above if you're feeling adventurous) that interplanetary cosmic dust has more exotic elements and compounds related to its nearby bodies - e.g. planets, comets, the local star etc.
Yeah!? And?
So we have a precedent for Barnacles extracting material from a planet to create something useful for the Thargoid ships (as well as meta alloys - which appear to be nothing but a byproduct from whatever the Barnacle is doing). It must be something about the confluence of planetary makeup, in conjunction with the nebulae, make that possible - surely?
If so, then it's reasonable to suggest that the same will be true for this mothership - but perhaps on a different scale - and that there's some local conditions which make a location ripe for whatever the hell it is that video is showing us. Again - the planet that's 'thargoformed', but also perhaps nearby *planetary* dust (and possibly that from a nearby nebula too).
So I'm thinking it just reinforces the idea that others have already mentioned, that if this cave can be found, there's a high likelihood of it being in the nebulae where we've found the barnacles already - but also on the moons of planets a particular type, too.
Perhaps the UP has the answer to that one?
Actually, as I read all that back, I'm not entirely sure I'm really making much of a point!
- And it could just be that this mothership, if that what it is, instead of 'growing' on the planet, flies
to that planet and, kinda, burrows into it. But I can't work with that, so I'm going with my first idea!
Time to get flying, and
put the keyboard away!