Assertion: moon | /r/HasProperty | ariel
Facets:
Source sentences:
text: Eventually, the next two moons, Ariel and Umbriel, were discovered by William Lassell in 1851.
text: The names of all four satellites of Uranus then known were suggested by Herschel's son John in 1852, at the request of William Lassell, who had discovered the other two moons, Ariel and Umbriel, the year before.