Cocoon

Cocoon has 11 total collectibles known as Moon Ancestors. These can be acquired as you play through the game, or easily mopped up using chapter select once you finish the story. They are most often hidden just off the main path; may involve a small and simple puzzle, and are unlocked with an interaction.
7:55 - 84% - The Space Between The Stars
Take the white orb into the orange dimension. Use its power to traverse the gap on the right. Once across, go through the teleporter, swap the white orb for the green orb and go back to the orange world. Go up the pillars to find this easy moon ancestor.

CHAPTER 5 - THE SPACE BETWEEN THE STARS ACHIEVEMENT

You unlock this by interacting with the Moon Ancestor in level 5, you can find this using this guide to help you get through chapter 5 to get all of the achievements on that chapter, the Space Between the Stars achievement drops just around the 14:00 mark.

Check the guide below, you need to load at 84%


Timestamps:

00:00 Intro + 0-14% + Off the Beaten Path Achievement
04:49 14% - 17% + Pathfinder Achievement
06:37 17% - 24% + Mariner’s Branch Achievement
09:50 24% - 27% + Mesh Network Achievement
11:12 27% - 32% + Fundamental Changes Achievement
14:01 32% + End of the Line Achievement
14:40 32% - 46% + Skin Deep Achievement
21:45 46% - 52% + Different Destinations
26:26 52% - 56% + From There to Here Achievement
28:21 56% - 63% + Conduit Achievement
32:48 63% - 73% + This Has Potential Achievement
38:59 73% - 81% + Cryptographer Achievement
43:08 81% - 84% The Space Between the Stars Achievement
46:09 84% - 86% + A Perspective on things Achievement
47:26 86% - 90% + Daybreak Achievement
55:13 90% - 97% + Loophole Maneuvers Achievement
1:00:23 97% - 100% Cosmic Architect Achievement