Perched on a mesa just above Flagstaff is the historic Lowell Observatory, founded back in the days of the Wild West. Observatory director Jeffrey Hall talks about landmark discoveries made there, like 'Planet X'—later renamed Pluto—and the exoplanets astronomers are spotting there today.
位于弗拉格斯塔夫上方山丘上的是历史悠久的洛厄尔天文台，它建立于西部蛮荒时代。天文台台长杰弗里-霍尔（Jeffrey Hall）谈在那里取得的里程碑式的发现，如 "X行星"——后来改名为冥王星——以及今天天文学家在那里发现的系外行星。