Ko Messier 81 (e mohiotia ana ko NGC 3031 ranei Bode's Galaxy) he kopae kopae tata ki te 12 miriona marama-tau te tawhiti, me te diameter o te 90,000 marama tau, tata ki te haurua o te rahi o te Milky Way, i roto i te whetu Ursa Major. Na te tata ki te whenua, te rahi nui, me te karihi kopae kaha (e mau ana i te 70 miriona M <unk> supermassive black hole), kua akohia a Messier 81 e nga tohunga tohunga tohunga. Ko te rahi o te kopae kopae me te maarama nui e tino rongonui ana mo nga tohunga tohunga tohunga. I kitea tuatahihia a Messier 81 e Johann Elert Bode i te Tihema 31, 1774. Na reira, i etahi wa ka kiia te kopae kopae ko "Bode's Galaxy". I te tau 1779, ka tautuhi ano a Pierre Méchain me Charles Messier i te ahanoa Bode's, i muri mai ka whakararangihia i roto i te Messier Catalogue.
12 miriona