Start: Talk to the Observatory Professor in the Observatory Reception Room.
Skills: Level 10 Crafting, and the ability to defeat a level 42 monster.
Quests: None!
What You Need: 3 Wooden Planks, a Bronze bar, Molten Glass, and a Lens Mold.
--------------------------------------------------------------------------------
Getting Started
Firstly, speak with the Observatory Professor, located in the Reception Room of the Observatory (near the Observatory Town). Ask if you can look through the telescope, and he says that it's broken. He tells you that a family of Goblins has tampered with the telescope, so ask if you can help. He says that he needs some wood for the Tripod, bronze for the Tube, and glass for a new Lens.
Fixing the Telescope
You can find the 3 Planks needed to fix the telescope just north of the Barbarian Outpost, which is to the far north of Ardougne. A Bronze Bar can be Smithed by anyone, or you can buy one. A piece of Glass can be made by using your Crafting skill. Once you have these 3 items, bring them back to the Professor who will take them from you. He then says that he needs a mold so that he can make a new Lens.
Now go down the ladder in the Reception Room to find a cavern. You'll need to search each of the chests located in this cavern until you find a Keep Key. However, be aware that if you open a chest that doesn't contain a Keep Key, you'll be attacked by a level 31 Poisonous Spider.
Once you have the key, you'll be able to open the Keep Gate. From the ladder, head east and then north. Follow the passage west until you come to a Keep Gate guarded by a level 42 Goblin Guard. Prod him to wake him up, and he will attack you.
After killing him, use the key with the gate to unlock it, and then search the stove to find the Lens Mold. Bring this back to the Professor, who now says that he doesn't have a high enough Crafting level to make the Lens for the Telescope. He gives you the Glass and the mold back, so just use the molten glass with the Lens Mold to Craft him a new Lens. Give it back to him, and he wants you to visit him in the Observatory.
Climb back down the ladder into the maze, and head all the way back to the small room with all of the passages leading from it. Now, instead of taking the southeast path, take the northeast-most passage to find a ladder leading to the Observatory. Talk to the professor, and then "Use" the Telescope to see a constellation. After closing the window the Professor should talk to you again. You can choose either option, and you should get your reward in your Backpack!
Rewards
Your item reward depends on what Astrological Sign you see when you look through the Telescope and it is also different for each person.
The Spirit of Scorpius will now give you a mould to make Unholy Symbols, and he will bless them for you too. He can be found in the graveyard north of the Observatory.
2,350 Crafting Experience
2 Quest Points