Dirt wasn't "discovered" in the same way that a new species or scientific phenomenon is. It's been around since the Earth formed billions of years ago.

Here's why the question is a bit tricky:

* Dirt is a natural process: It's formed by the gradual breakdown of rocks, minerals, and organic matter. This process happens continuously.

* Humans have always interacted with dirt: Early humans used dirt for various purposes, like building shelters, growing crops, and creating tools.

* The word "dirt" itself is relatively recent: It evolved from older terms like "earth" and "soil," reflecting a growing understanding of its composition and importance.

So, while we can't pinpoint a specific date for the "discovery" of dirt, it's been an essential part of our planet and our lives since the beginning.