Assertion: asteroid | /r/HasProperty | remnants of a planet
Facets:
Source sentences:
text: The discovery of three more faint objects in similar orbits over the next six years—Pallas, Juno, and Vesta—complicated that elegant solution to the missing-planet problem and gave rise to the surprisingly long-lived though no longer accepted idea that the asteroids were remnants of a planet that had exploded.
text: One theory suggests that they are the remains of a planet that was destroyed in a massive collision long ago.