Assertion: comet's nucleus | /r/HasProperty | rock
Facets:
Source sentences:
text: A cometary nucleus is composed of rock, dust, and frozen gases.
text: A comet is a small body in the solar system that orbits the Sun and (at least occasionally) exhibits a coma (or atmosphere) and/or a tail - both primarily from the effects of solar radiation upon the comet's nucleus, which itself is a minor body composed of rock, dust, and ice.