Stars of Ursa Major with noticeable shape of Big Dipper with seven bright stars over an astronomical instrument known as armillary sphere. The various shape of the istrument in has been used by Greek, Persian and Arabs, Chinese and later by European astronomers to measure the coordinates of the celestial bodies. P.K. Chen.转一张算了,怕侵权,想看的可以去这里:http://www.twanight.org/newTWAN/photos.asp?ID=3001658&Sort=Country