圣诞节是一个历史超过两千年的节日。当我们提起圣诞节，我们往往会想到装饰品、闪亮的灯饰、瑞雪、礼物和圣诞树。

然而，你知道圣诞树上挂的星星的由来吗？

诞节是庆祝耶稣诞生的节日，在基督教的信仰中，他是上帝之子。于两千多年前，乔瑟夫和他大腹便便的妻子玛利亚必须离开家园，长途跋涉到伯利恒。伯利恒为古代以色列的城市，位于约旦河西岸，距耶路撒冷仅有数公里之遥。

当他们抵达伯利恒时，当地所有的旅馆都客满，因此他们找不到地方过夜。更糟的是，玛利亚又即将临盆。最后一名好心的男子让他们借住于马厩中，与驴子和羊只同睡。耶稣于当晚出生，由于那里没有床，所以他只好睡在马槽里。

当天夜晚，马厩上空升起了一颗明亮的星星。三位智者看到这颗星星，便明了那是上帝的启示。他们追寻着星星，找到了耶稣、玛利亚和乔瑟夫。为了庆祝耶稣的诞生，他们分别送了一样礼物给耶稣。

这就是为什么我们会在圣诞节互换礼物的原因。

Have you ever wondered about the real origin of the star that shines atop many a Christmas tree? The story of Jesus' birth in the Bible talks about a star guiding the "Three Wise Men" to the manger, the star heralding the birth of a king. But did that star actually exist? Astronomers in London have been trying to find out.

Looking out across snow-covered London is the Greenwich Royal Observatory.

At the Astronomy Centre, public astronomer Marek Kukula explains that despite the precise records of star movements kept by the Chinese at the time, there is no precise date for when the Wise Men tracked the "star", so it is difficult to know precisely what they witnessed.

One theory is that it was a conjunction of planets, where two or more planets seem to pass close together.