They're basically made up of debris left over from theoriginofthesolarsystem.
它们基本上是由太阳系起源时遗留下来的碎片组成的。
2
(Astronomy) the nebular hypothesis oftheoriginofthesolarsystem.
(天文学)关于太阳系起源的星云假说。
3
The Oort cloud is a vast belt of dust and ice that is believed to lie around one light year from the Sun and is theoriginof many of the comets that pass through our solarsystem.