The type of precipitation that forms when water vapor changes directly into a solid is snow.

Here's why:

* Sublimation: The process of water vapor changing directly into a solid is called sublimation.

* Snow Formation: When water vapor in the atmosphere cools to below freezing temperatures, it undergoes sublimation and forms tiny ice crystals. These ice crystals then collide and stick together, forming snowflakes.

Let me know if you'd like to know more about how snowflakes form!