Mapping of multiple in-game planets

[isostone]

Hello! I'm currently working on a project for a character who is a amateur (but enthusiastic) cartographer. They exist in the world of Outer Wilds, a game with multiple simulated planets(none more than a few kilometers in diameter). The simulated planets each have their own gimmicks (i.e Brittle Hollow, a hollow planet with a black hole in the center. Its crust falls into the black hole during gameplay, and most of what you can explore is under the crust).
How might I go about mapping these places in a way that'd be accurate and believable in the sense that my character could have drawn them up while exploring? What sort of notes should I be taking?

Comments

[isostone]

The plan is to note down major landmarks (most of which are ruins of an alien species in game, but I plan on adding in a few geological ones as well).

[silveradept]

Okay, so what's the purpose of the map? Is it to show the distances between the landmarks? A pathway to get between them? Their relationship to a single orienteering point? Relative heights and depths? What's the map going to be used for? Once that gets established, it well suggest what pieces of data are important and need to be noted and which ones aren't.

[isostone]

The purpose of the map is for this character to document their findings(so notes on what was found in a place and points of interest there), and also how to travel between several different landmarks. Height and depth won't be noted except in certain circumstances in which its relevant.

[silveradept]

This feels like multiple maps, then, one for each planet visited, with notes on how they arrived and the distances between planets in addition to the local features and distances between them. The small maps then can possibly be stitched together after an exploration session into something bigger and more complete, and in bigger scale.

[isostone]

That definitely sounds much more manageable than what I was thinking of. Thank you for the suggestion!