It was all skybox matching at first.
IMPORTANT NOTE : I have literally ZERO idea about how the system/planet was found. I just joined Alex in voice who straight told me about CJ's lead, that is all. The skybox match I tried was strictly done once in orbit of the planet.
Really an hit and miss, I circled around the planet several times until I thought of being close enough. Glided down to the surface, straight toward the canyon that was under me. From there just following the canyon's general direction; there was an awful lot of surface POIs on my radar in that area, I aimed at them at first but was only finding System Defense Force vessels every single time, which led me into a circling chase of about 50kms in radius, until I had the Milky Way's bright light contrasting with the surface on the screen (not even talking about the ambient occlusion near fat rocks on the ground that let you think you found something, the deception every time
).
There was an object near a few rocky ridges that was creating some aliasing with the heavy contrast right in the middle, so I headed there, and bam.
I realized long afterward that it wasn't the same as the trailer, I was so focused on the background that I entirely forgot to compare.
Of note, I spent a few thousand hours licking planetary surfaces back during the CoR exploration CG in search for the bases, so had a fair few ideas of how to "enhance" the yoghurting experience already
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About the above : Reduce all your graphic settings to the absolute minimum (planets looks like yoghurt at this stage, hence the term), try to find "contrasty" lighting conditions, and something I like doing : licking the surface upside down with the camera angled straight up your head
I think this really shows that FD are missing out on a lot of potential gameplay here.
This sounds... pretty awful to do, over such a huge area.
Now, I'm not saying gameplay wasn't there for this, as I've previously found actual in game clues to things, often they are overly obfuscated for really, quite little reason when the actual thing you are finding has such a small consequence, but sometimes it seems to work.
I went to this place tonight, and the audio logs are nice, I love that FD are adding this stuff into the game it's desperately needed it.
I really do feel like Q4 is way too late to be adding the new exploration tools though, when things like this (and I suspect many many others) are hidden out there for the narrative of 2.4, and they are still relying on.... lowering graphics settings, flying upside down, even assuming you have the right planet (did the other planets even get looked at first? this is one hell of a fast find) it's pretty silly as the way to find things in the game.
At least they do have some mechanics now, to at least lead you to systems, and planets, via listening posts, local herald news, and various installations/megaships etc, via the data link scanner, but I feel like once your at the planet, unless the hints have given you direct co-ordinates, it's a little bit mental to manually scan the surface by eye alone.
Well done for finding it, however you managed it, some people have insinuated game files/hacking etc, I wouldn't accuse people of that, but for me, honestly, if someone DID use that method, I'd count it as just as, if not MORE valid than using the in game methods, because it's likely less tedious, possibly more fun to do that, than lowest settings upside down planet surface scouring...
INRA bases is cool though, and it was nice to get the audio logs. I just checked the location here, and went there myself without spoiling the logs, and would advise others to do that whenever these things come up (unless you have any lead yourself! dont want to spoil one you actually managed to follow the micrscopic bread crumbs to!)