Mars（火星）前要不要加冠词

不需要的，例如A change in Mars' climate may have killed off primitive life forms early in the planet's history. If so, we may find fossilised evidence of life on Mars. Only time will tell.

上面是英国BBC网站上的一个句子，见
http://www.bbc.co.uk/science/space/life/looking/mars.shtml

要加 因为火星是独一无二的 比如 the earth，the moon