Observatory Quest

Walkthrough
Talk to the Observatory Professor and ask to look through his telescope. He tells you that the Goblin residents have been causing trouble and tampered with it. He asks you to collect 3 different items. Hand in all 3 items, and he will return the molten glass while asking you to find the lens mould.

Lens mould
Go down the ladder in the Observatory post, into dungeon. Go through the maze to the far south west corner and you find a chest containing a keep key. Go to the room where a level-48 Goblin guard is (labeled "keep" on the map), kill him and use key on the gate. Search the sacks to find lens mould.


 * The Goblin guard does not need to be killed in order to open the gate. It is possible to simply fight him for the first 3 mandatory rounds of combat, retreat and quickly use the key on the gate, which will allow you to pass through it. 

Go back to the Observatory post and give the lens mould to the Professor. Agree to help him make the lens. Use molten glass on the lens mould and then talk to the Professor and he will tell you to meet him in the Observatory.

Go back down to the dungeon, and through the maze, and find another ladder north of the chest containing the key to the gate. It leads to the Observatory. Talk to the Professor and look through the telescope to get a constellation.

Finishing up
After looking through the constellation, either continue the talk with the Professor or look again through the telescope if you want another roll at the possible constellations, leading to a distinct dialogue case and reward.

Rewards

 * 2 Quest Points
 * Crafting experience: $$Level * 100 + 250$$
 * 350 xp at level 1
 * 1550 xp at level 13
 * 5050 xp at level 48
 * 5450 xp at level 52


 * Depending on which constellation you last observed:
 * Aquarius:  [[File:Water-Rune.png]] 25 water-runes
 * Aries: Attack experience - $$Level * 25 + 125$$
 * 150 xp at level 1
 * 875 xp at level 30
 * Cancer: [[File:Emerald Amulet of protection.png]] Emerald Amulet of Protection
 * Capricorn: Strength experience - $$Level * 25 + 125$$
 * 150 xp at level 1
 * 875 xp at level 30
 * Gemini: [[File:Black 2-handed Sword.png]] Black 2-handed Sword
 * Leo: Hits experience - $$Level * 25 + 125$$
 * 875 xp at level 30
 * 2550 xp at level 97
 * Libra: [[File:Law-Rune.png]] 3 law-runes
 * Pisces: [[File:Tuna.png]] 3 Tuna
 * Sagittarius: [[File:Maple Longbow.png]] Maple Longbow
 * Scorpio: [[File:Weapon poison Potion.png]] Weapon Poison
 * Taurus: [[File:Super strength Potion.png]] Super Strength Potion (3 dose)
 * Virgo: Defense experience - $$Level * 25 + 125$$
 * 875 xp at level 30
 * 1,325 xp at level 48
 * 1,525 xp at level 56
 * [[File:Uncut sapphire.png]] Uncut sapphire

Optional: Unholy symbol mould
Speak to the Spirit of Scorpius, at the graveyard to the north. He will give you an Unholy Symbol mould, which you can use to make Unholy Symbols of Zamorak. If asked, he will also bless these symbols.

Glitch
Although the making of the lens requires a crafting level of 10, it can still be done (without boosting) if the player's crafting level is below that level producing the message:
 * "Sorry, you need a crafting level
 * Of 10 or above to use this object
 * You pour the molten glass into the mould
 * And clasp it together
 * It produces a small convex glass disc"

Trivia

 * After you have repaired the telescope talk to the Observatory assistant and he will give you a jug of wine.
 * Once the player finishes the quest, they will always see with the telescope the Scorpio constellation.