唐朝刘方平有诗曰:“更深月色半人家,北斗阑干南斗斜。”初读此诗,多数人会将“北斗”认为就是“北极星”,其实两者风马牛不相及。我们要认识北极星,因为北极星除了能让人确定方向之外,还有许多作用:确定当地的地理纬度,掌握天球的座标,估算月份和季节,计算当地时间等等。一、? The Tang Dynasty Liu Fangping had a poem saying: “A darker moonlight half family, and the Beidou is a dry south.” When you read this poem for the first time, most people think of the “Beidou” as a “Polaris”. In fact, the two have nothing to do with each other. We need to know Polaris, because apart from being able to determine direction, Polaris has many other functions: determining the geographic latitude, grasping the coordinates of the celestial sphere, estimating the month and season, calculating the local time, and so on. one,?