 The search for rings was motivated in part by a desire to avoid damage to "New Horizons" when it passed through the Pluto system in July 2015.Further observations were made on 3 and 18 July 2011 and Kerberos was verified as a new moon on 20 July 2011.It was later precovered or identified in earlier archival Hubble images from 15 February 2006 and 25 June 2010, though Kerberos was obscured by diffraction spikes in those images.