What is an asteroid called if it is in deep space?
We have only discovered one such object so far: ʻOumuamua. (Although a second, 2I/Borisov, was discovered in 2019) The general practice has been to call it an &quot;interstellar asteroid&quot; or &quot;interstellar comet&quot;, even though it is not in orbit.  You could just call it an &quot;interstellar object&quot;.