Found this too. Sorry for wall of text. Also note that some of the events are 10levels above the supposed level cap of the game. Hard is not the right word I think, judging on how tough some enemies already can be.
Reddit user KingOfCarrotFlowers put together a list of all the maps and missions that have been discovered thus far and featured on DestinyDB after being data mined from the beta and companion app.
======Crucible Maps======
Earth:
Twilight Gap
Rusted Lands
Exodus Blue
Moon:
First Light
The Anomaly
Mars:
Bastion
Firebase Delphi
Blind Watch
Venus:
Asylum
Shores of Time
Mercury:
The Burning Shrine
(All maps include Clash, Skirmish, Rumble, Control, and Salvage game modes)
======Crucible Game Types======
Trials of Osiris (Skirmish): 3v3. You have caught the eye of Osiris. Venture to Mercury and prove yourself as one of the Crucible’s elite. Only the worthy may face the Trials of Osiris, for only the worthy are strong enough to endure what is to come. A string of victories will earn great rewards – but lose three times and you’re out.
Iron Banner: 6v6. Champions are born in battle. Prove your might and earn the respect of the Lords of Iron.
The Grand Arena (Rumble): 3v3. Prove your merit to the New Monarchy in pure combat. You against all. Hone your Light by challenging your fellow Guardians in a fight for survival.
Dead Sectors (Control): 6v6. Dead Orbit desires new territories to expand their reach beyond the City. Fight for control of strategic battle zones. Hold your ground to gain the momentum.
Ancient Relics (Salvage): 3v3. The Arachs of Dead Orbit covet rare artifacts. Secure and defend the Relics to claim the secrets of our past.
Executor’s Challenge (Skirmish): 3v3. New Monarchy seeks those capable of reclaiming the frontier, one battle at a time. A focused engagement between two fireteams. Teamwork is your greatest weapon.
Eternal War (Clash): 6v6. The Future War Cult seeks champions who can face the inexorable future. Form an alliance and fight for supremacy across the ruins of our old worlds.
Machines of War (Combined Arms): 6v6. Heed the call of the Future War Cult and master war on a massive scale. Coordinate vehicles and your ground game to control the battlefield and rout your opponents.
======Social======
The Tower
======Exploration Areas======
Venus: Ishtar Sink
Earth: Old Russia
Moon: Sea of Storms
Mars: Meridian Bay
======Raids======
Venus: Vault of Glass (levels 27, 30, 31)
======Story Missions======
Earth:
A Guardian Rises (level 1)
Restoration (levels 2, 5)
The Dark Within (levels 3, 6)
The Warmind (levels 4, 7)
The Last Array (levels 5, 8)
Moon:
The Dark Beyond (levels 6, 9)
The Sword of Crota (levels 7, 10)
The World’s Grave (levels 7, 10)
Shrine of Oryx (levels 8, 11)
Chamber of Night (levels 8, 11)
The Reef (Asteroid Belt):
The Awoken (level 10)
A Key Awaits (level 12)
Venus:
A Stranger’s Call (levels 10, 12)
Ishtar Collective (levels 10, 12)
The Archive (levels 11, 13)
Scourge of Winter (levels 11, 13)
Eye of a Gate Lord (levels 12, 14)
Mars:
Exclusion Zone (levels 15, 17)
The Garden’s Spire (levels 16, 18)
A Rising Tide (levels 17, 19)
The Buried City (levels 17, 19)
The Black Garden (levels 18, 20)
======Story Challenges======
Earth: The Queen’s Wrath (Kill Order; level 24)
======Strikes======
Random:
Vanguard Eagle launches a random strike at level 18
Vanguard Viper launches a random strike at level 20
Vanguard Wolf launches a random strike at level 22
Vanguard Tiger launches a random strike at level 24
Earth:
Nightfall: The Devils’ Lair (levels 22, 26, 28)
The Devils’ Lair (levels 6, 8)
Moon:
Nightfall: The Summoning Pits (levels 22, 26, 28)
The Summoning Pits (level 12)
Venus:
Nightfall: The Nexus (levels 22, 26, 28)
Nightfall: Winter’s Run (levels 22, 26, 28)
The Nexus (level 14)
Winter’s Run (level 14)
Mars:
Nightfall: Cerberus Vae III (levels 22, 26, 28)
Cerberus Vae III (level 18)
Dust Palace (level 18)
Note: The “Nightfall” strikes may open up for limited times on rotation, rather than being available at all times
======Items======
262 helmets
178 chest armors
217 class items
244 gauntlets
181 leg armors
169 primary weapons
120 special weapons
85 heavy weapons
74 ships