Here's why:

* Liquid water: Earth is the only known planet in our solar system with abundant liquid water on its surface. This is essential for the formation of sedimentary rocks.

* Weathering and Erosion: Earth's atmosphere and climate create conditions for weathering (breaking down rocks) and erosion (transporting weathered material). This is crucial for the creation of sediments.

* Deposition: Rivers, oceans, lakes, and other bodies of water carry sediments and deposit them in layers. Over time, these layers are compacted and cemented, forming sedimentary rocks.

While other planets and moons may have water in various forms (e.g., ice, water vapor), Earth is the only one with the combination of liquid water, active geological processes, and a long history of these processes that allow for the formation of sedimentary rocks.