Raft survival, Selene. Where are the keys?

How to get the Selene key of raft survival;

Before entering the observatory, you will pass a section of iron fence, and you can find a note on the iron fence on the right.

When you walk in, the snow surface collapses and you need to swim a short waterway. Attention? ? ? ? Fish. After crossing the waterway, climb the ladder into the house.

There are two notes on the table on the first floor;

There is a note on the table on the second floor;

There is a note next to the safe on the third floor;

There are two notes on the fourth floor (attic).

The password of the safe is to find the corresponding constellation according to the note prompt, and count the number of corresponding constellations through the poster on the wall. The password is 5964. Open the safe to get the blueprint of advanced mooring anchor+Selene key?