China will see the longest total solar eclipse in 500 years on July 22, a scientist said Saturday. The prime time of the total eclipse was expected to begin from 9 a.m. to 9:38 a.m. (Beijing Time), said Wang Sichao, a research fellow with the Nanjing-based Purple Mountain Observatory under the Chinese Academy of Sciences. People watch the newly-installed equatorial sundial, measur...[繼續(xù)閱讀]