Yes, technically an asteroid can be the size of a pebble. There's no official minimum size for an asteroid.

Here's why:

* Definition: Asteroids are rocky or metallic bodies orbiting the Sun, primarily found in the asteroid belt between Mars and Jupiter.

* Size Range: Asteroids vary immensely in size, from a few meters to hundreds of kilometers across.

* Smaller Bodies: Smaller rocky bodies in space are often classified as meteoroids. However, the distinction isn't always clear-cut, and a pebble-sized object orbiting the Sun could be considered a very small asteroid.

So, while a pebble-sized asteroid is extremely small, it's not impossible.