The Oort Cloud is the origin of long period comets.

奥尔特云是长周期彗星的起源之处。

However, calculating how many there are using long period comet observations, you wind up getting about 400 billion.

然而，如果用长周期彗星观测来计算有多少彗星，你最终会得到大约4000亿颗的答案。

Instead, their orbits are tilted in all different directions, more like the way long period comets are scattered around the Sun.

相反，它们的轨道向各个不同的方向倾斜，更像长周期彗星分散在太阳周围的方式。