“…Results of the 17 July 2017 stellar occultation by Ultima indicate that this object displays a very irregular shape and could even be a close or contact binary (Buie et al, , ; Zangari et al, ). Binaries are common in the Kuiper Belt (Noll et al, ), including contact binaries (Lacerda, ; Lacerda et al, ; Thirouin et al, ; Thirouin & Sheppard, ), and it has been argued that many short period comets, such as 67P/Churyumov‐Gerasimenko, 8P/Tuttle, and 103P/Hartley 2, and even 19P/Borrely and 1P/Halley, were formed as or evolved to be contact binaries (or more generally, bilobate bodies; Harmon et al, ; Nesvorný et al, ; Rickman et al, ), albeit from smaller components than the ostensible components of Ultima. Gravitational collapse of “pebble clouds” in the solar nebula is predicted to have naturally and efficiently formed binaries in the Kuiper belt, and with subequal mass ratios (Nesvorný et al, ).…”