Do astronomers generally agree that the distinction between comets and asteroids is not so clear? edit: I just saw this tweet and find it incredibly relevant :)



begin question: See this answer and then consider if there are known or likely solar system bodies that might be identified as both asteroids and comets.
If so (there seems to be an example there) would this be because there is insufficient information known about the body, and the ambiguity could be cleared up with enough data (say a visit by a spacecraft)?  Or are the categories of asteroids and comets actually overlapping?
If the latter, is there work underway to improve or update these definitions?
If we're going to get technical, Asteroids are not really an official name anymore. In 2006, when the IAU redefined what a planet was (and thus demoted Pluto), they also decided to more formally define other terms to identify objects in our solar system. You can see a diagram of all the official terms and how they relate below. Notice the important factor that asteroids no longer made the cut. There is the collection of &quot;Small Solar System Bodies&quot; (SSSB) and within that falls comets and centaurs, but asteroids are not exclusively called out.

So if you want to get technical, asteroids are really SSSBs now and comets are SSSBs as well, but also happen to fit into the sub-category of comets. What defines an SSSB as a comet is its ability to form a coma based on the sublimation of icy surface volatiles. So you might distinguish an &quot;asteroid&quot; as an object which cannot form a coma (and orbits inside Neptune), but that still leads to an ambiguity because what happens when a comet runs out of surface volatiles? Does it now become an asteroid? Is it still considered a comet? There are no clear answers.