Observatory Quest

Obtain a bronze bar, 3 planks, and molten glass.

Talk to the professor three times (until he takes all of the above items).

Leave the house and go east to the abandoned buildings.

Climb down the stairs in the western building.

Open and then search specific chests for a goblin kitchen key.

Be sure to finish the dialogue after searching to receive the key.

Every dead end will have a searchable chest. Head south (and slightly east) first and if the key is not found in the two chests directly south from the stairs, it is guaranteed to be in the far south-east chest in the dungeon.

Go back to the staircase at the entrance, but do not exit the dungeon.

Go east, then north, and then head west until a guard is seen guarding a kitchen.

Kill him or lure him away from the kitchen.

Inspect the stove in the kitchen to receive lens mould.

Return to the surface and talk to the professor.

Use the lens mould on the molten glass.

Talk to the professor.

Go back to the abandoned building and climb down the stairs.

Head to the southern section and climb the stairs to the observatory, as indicated on the map.

Watch the cutscene.

Go upstairs. Look through the telescope and identify which constellation is seen (see table below).

Talk to the professor and tell him which constellation was seen.

Quest complete!