Even if you're not an astronomy buff, chances are you caneasily recognize certain constellations and stars such as the Big Dipper, Orion's Belt and the North Star.
即使你不是一名天文学发烧友，你也能轻易地辨认出某些星座，比如，北斗七星，猎户座的腰带，还有北极星。
The North Star is the brightest star in the constellation known as the Little Dipper.
北极星是小熊座中最明亮的一颗星。
It is so-called because of the special position it occupies relative to Earth's axis.
它的名字源于它所处的特殊位置，这个位置与地轴有关。
If you were to stay up all night gazing at the stars, you'd slowly see them revolve around a point in the sky known as the North Celestial Pole.
如果你熬夜盯着满天繁星看，会慢慢发现它们都绕着天上的一个点旋转，这个点就是北天极。
You would notice, however, that one star remains stationary.
这时，你会注意到有一颗星星一动不动，它就是北极星。
This is the North Star, so named forits location almost directly in line with the North Celestial Pole.
北极星因自身位置几乎与北天极重合而得名。
Due to its consistent position in the sky, at one time sailors used the North Star as a navigational tool.
由于北极星在天上的位置永远不变，所以曾经一度，水手们将北极星作为导航工具。
By measuring the angle between the northern horizon and the North Star, a navigator could accurately determine the ship's latitude.
通过测量北方地平线与北极星之间的角度，导航员能确定船只所处的纬度。
But latitude, or the imaginary lines stretching across the globe parallel to the equator, was notenough to pinpoint a ship's location.
但纬度，或者，想象中与赤道平行环绕地球的那条线，不足以确定船只的位置。
Knowing latitude only allowed navigators to locate themselveson a particular latitude line at a particular distance from the equator.
知道纬度，导航员也只能确定自己在哪条纬线上，距赤道有多远。
It was only with the inventionof a way to accurately measure longitude that precise navigation became possible.
只有发明出测量经度的方法，进行准确的导航才会成为可能。
Although the North Star is no longer used by navigators, it remains a heavenly icon of humancuriosity and exploration.
尽管如今导航员已不靠北极星来导航。但它代表着人类永恒的探索与开创精神，将永远在天空中绽放光芒。
