Activate Chromatic Orrery's first ability by tapping it, adding ({5} magic symbol) .
Cast Ancestral Statue by paying ({4} magic symbol) .
Alela triggers, creating a 1/1 Faerie creature token.
Resolve the Ancestral Statue spell.
When Ancestral Statue enters the battlefield, it triggers.
Holding priority, activate Clock of Omens by tapping Ancestral Statue and the Faerie, untapping Chromatic Orrery.
Resolve the Ancestral Statue trigger, returning it to your hand from the battlefield.
Repeat.
Once you have infinite mana, you may instead use Chromatic Orrery's last ability to draw infinite cards, or you may untap any other artifact(s) you control.