The rings were directly imaged when the "Voyager 2" spacecraft flew through the Uranian system in 1986. Two more faint rings were revealed, bringing the total to eleven. The Hubble Space Telescope detected an additional pair of previously unseen rings in 2003–2005, bringing the total number known to 13. The discovery of these outer rings doubled the known radius of the ring system. Hubble also imaged two small satellites for the first time, one of which, Mab, shares its orbit with the outermost newly discovered μ ring.