Ghost of Promise
You can begin this mission during your very first visit to Eos, but won't be able to complete it until some time later. This is a type of quest you'll see a lot of Andromeda. It'll begin when, after clearing out a random Remnant site, you'll find a datapad.
This will have a fragment of info about an Initiative researcher lost on Eos- Ana Carrell. You'll have to comb other Remnant sites to find more datapads, but the locations are determined randomly (though you always find the pads in the right sequence). Find enough, and SAM will produce a nav point that leads to some sort of resolution.
In this case, you can't reach the final navpoint until the planetary radiation clears, so stick a pin in this one. There's an unmissable conversation on the bridge of the Tempest that will tell you when Eos' climate improves. When that happens, NOMAD on over to the nav point- a Remnant mini Vault.
There's nothing in the entry hall, so take the gravity well down. As you land, Ana's last data pad cache is to the northwest.
Read them to confirm that Ana is dead. Your next quest objective is now in Prodromos, but if you want to linger here, there is a container on the top platform, well behind the console, and one by a pillar on the low platform to the south east
If you're ready for a fight, use the Remnant Console to unlock the far door. Opening this releases a Destroyer, probably the one that fatally wounded Ana
There's a lot of cover here, but the small outcroppings don't offer the protection that the giant pillars do. Use those as your primary safe point to take out the thing's turrets, then the monster itself.
There's a sealed Remnant contain in the room where the Destroyer was trapped. Solve the decryption to open it.
The other door is permanently locked, but do scan the data core and loot the ordinary container before heading back up. Before you leave, there are a few mineral deposits in the crater here you can scoop up, and a cadmium sample for the Hitting Rocks for Science task.
When ready, return to Prodromos and tell the tale of Ana's bravery type your report up on the objective'd terminal, closing out the quest.