Finally, I've gotten them all! : r/outerwilds

Endings - Official Outer Wilds Wiki

Outer Wilds Achievement Guide

The new achievements can be seen on steam : r/outerwilds

New unnamed achievements were just added to Outer Wilds on steam. : r/ outerwilds

Spoiler?] Updated Steam achievements? : r/outerwilds

Outer Wilds Achievement Guide 100% PC Achievement Guide

Steam Community :: Guide :: Easy Deep Impact Achievement Guide

EOTE *minor* spoiler] Artstation has some images from concept art for the DLC. There are 14 achievements in-game, but 15 on the art-station. Any guesses as to what this achievement would've been

Achievements - Official Outer Wilds Wiki

Outer Wilds - Ash and Ember - Fangamer