Remnant Data Core Nodes
During your travels around Eos - particularly the western half of Eos - you’ll come across Kett camps, which randomly might contain Remnant Data Core Nodes (not to be confused with the Remnant Data Cores that Peebee wants for the quest "Task: Remnant Data Cores". The camps are unmarked, and whether a camp contains such a device is entirely random; a camp that was previously barren might later possess one, or a previously endowed camp might later possess a new one. Basically, the only way to find the numerous devices you need is to drive around Eos looking for Kett camps. SAM will warn you when such a device is present, but he’s not always great about telling you by just performing a drive-by in the Nomad, so you’ll have to get out and explore the camps.
Scan three of these devices and you’ll gain enough info for SAM to provide you with a navpoint. West-of-center of Presson Dunes you’ll find an island of rock in a sea of sand. On the eastern edge of this rock formation you’ll be able to find - and deploy - a Forward Station, after which drive up a road to the west. Don’t be married to the road, however, as it’ll only get you so far, ending well before you reach the navpoint. Make the west of the way across rough terrain and you’ll find a sunken Remnant structure along the western end of the rock formation.
Kett Coordinates and the Island of Stone
Enter the Remnant structure, open a door and use a Gravity Well to descend into the depths of the Remnant structure. When you land, immediately turn west and you’ll find a container protected by a Remnant Glyph. Gonna have to keep your eye out for glyphs to scan. Speaking of which, scan the wall to the west of this container to find one. Return back west and scan the southern side of the pillar east of the Gravity Well to find a second glyph. Two down, two to go.
Continue down a hallway to the east and exterminate a group of Kett, scan a Data Pattern that lines the hallway, then continue east, then north through a doorway. In the chamber beyond you’ll have to deal with a mess of Kett, including Chosen, Anointed and Destined, and fortunately there’s plenty of cover you can use to make the task of guarding the two ramps up to the southern end of the chamber easier. Crush the Kett and note there are two rectangular pits in this chamber, each of which have three pillars in them. Search the pillars in the southern pit, specifically the northern end of the western-most pillar here to find the third glyph.
Loot a container in the northwestern corner of the chamber, then go through a doorway to the north. In the next room you’ll find an Adaptive Remnant Core Device you can scan on an elevated square platform as well as the third and final glyph on the eastern wall. Loot a container to the north, head down a hallway to the west, scan a Data Pattern , then interface with a Remnant Console to the west to make a valuable discovery. Return to the beginning of this Remnant structure and, armed with all four glyphs, go solve that space Sudoku puzzle to nab the contents of the Remnant container it locks… or just use the provided solution.
Ride the Gravity Well out of the Remnant structure and return to Prodromos. Once there head east from where the Tempest is parked and enter the building lying in that direction, then log your findings on the Terminal there. Upload the data you pulled from the Remnant Console in response to the message "Request: Information on Eos" to finish the quest and earn 530 XP.