That's a good question! There are several possibilities depending on the size and origin of the object:

* Asteroid: A large, rocky body that orbits the Sun, mainly found in the asteroid belt between Mars and Jupiter.

* Meteoroid: A smaller rocky or metallic body that orbits the Sun. When it enters the Earth's atmosphere, it becomes a meteor.

* Comet: While comets are mostly made of ice and dust, they also contain rocky material. They have a tail of gas and dust that forms as they approach the Sun.

* Planetary debris: This includes smaller pieces of rock and metal that are remnants of planet formation.

* Spacecraft: While not naturally occurring, many spacecraft are made of metal and other materials, and can be considered rocky objects in space.

Let me know if you want to know more about any of these!