Composed of water ice;[57] named after Tenzing Norgay[58] Piccard Mons[n 14][59][60] ~5.5 km (3.4 mi)[56] 0.46 cryovolcanic (?) ~220 km across;[61] central depression is 11 km deep[56] Wright Mons[n 14][59][60] ~4.7 km (2.9 mi)[56] 0.40 cryovolcanic (?) ~160 km across;[59] summit depression ~56 km across[62] and 4.5 km deep[56] Charon Butler Mons[63] ≥ 4.5 km (2.8 mi)[63] 0.74 tectonic (?)