Update: Looking to fix the issue, Dark Nexis reloaded the game multiple times and discovered that their discoveries had not been wiped. It appears as though a caching issue causes a delay in discoveries being loaded into the game.
Some No Man's Sky players are reporting that their discoveries are being slowly wiped from existence in chronological order. According to the reports, the players revisited planets that they had discovered, even their home planets, and everything was as if they had never visited them
The names of every discovery, every plant, animal and vista named were gone. The only things that remained were the planet and system names.
Here's the account from Dark_Nexis:
"So as I got closer to the center I thought to my self I should head back home good thing I set a waypoint on my starting planet to find my way back. I finally made it back after many hours and I found out all my discoveries were wiped and it said I discovered it on the 11th when I started on the 9th.. I check a few neighboring stars I discovered and their discovers were wiped.. So none of my named animals plants were ever saved. The system name and planet names were saved but everything elts was wiped. I'm kinda sad that after heading back that all that I discovered was never really saved except the system and planet names.. What I mean by "wiped" is the names I gave them are gone and reset like I never discovered them, there still there just not discovered when I did discover t"hem before I left my starting system. Only thing still named is the planet and system names as said before.
Another user, Ultrasilvanus, chimed in claiming to have experienced the same issue, but added another detail:
"Just to be clear enough, discoveries are being erased in chronological order. First system, second system and so on. It's not random. It's a pattern, starting from your very first discoveries."
The players were able to return to their home planets by setting waypoints on their planetary map.
Is it a bug or is it intentional? It's hard to say, there's a very high chance that these discoveries were not saved due to the players being offline or servers being over-run at launch. There is another theory, however, that states the game can only contain a specific amount of discoveries, abandoning the earliest ones to make room for new ones.