Ursanis II was a class D planetoid in the Ursanis system, located ninety-six light-years from starbase Vanguard.
In late-2268, Ursanis II became the subject of a classified experiment conducted by Lieutenant Ming Xiong and the Starfleet science team in the Vault aboard Vanguard. An array of Mirdonyae Artifacts was used to manipulate spacetime to devastating effect, pulverizing the planetoid, then winking the debris out of existence. The destruction was monitored by the Anton-class starship USS Repulse, and its captain, Eugene Myers, reported the effects and sensor data to Lieutenant Xiong. (VAN novel: Storming Heaven)