Prior to the 2004 arrival of the Cassini–Huygens spacecraft, the rings of Saturn were widely thought to be much younger than the Solar System and were not expected to survive beyond another 300 million years.
在2004年卡西尼-惠更斯号太空飞行器到临之前，土星环曾被认为比太阳系年轻很多，並且不会再存在3亿年。