What is the origin of the idiom "on the horizon" and when to use it?

The idiom "on the horizon" can be traced back to the 17th century and has its origins in maritime navigation. Sailors used the horizon, where the sky meets the Earth, as a reference point. It later gained a metaphorical meaning for future events or developments that are expected soon. It is commonly used when discussing future trends, advancements, or significant developments in various fields such as technology, science, business, or social matters.