In the game Terraria, the Celestial Pillars, including the Solar Pillar, Vortex Pillar, Nebula Pillar, and Stardust Pillar, appear during the Lunar Events. These events are triggered once the Lunatic Cultist has been defeated. Each pillar represents a different damage type in Terraria: Solar for melee, Vortex for ranged, Nebula for magic, and Stardust for summoning.