Why do scientists think something could be hidden beyond the edge of our solar system?

为什么科学家认为某些东西可能隐藏在我们太阳系的边缘之外？

youdao

Why do scientists think something could be hidden beyond the edge of our solar system?

为什么科学家认为某些东西可能隐藏在我们太阳系的边缘之外？

youdao