When we look at gas clouds in space, we see stars forming, we see protoplanetary disks around them, we see the planets themselves getting their start.

当我们看着太空中的一团气体云时，我们能观察到恒星的形成，观察到它们周围的原行星盘，以及行星本身的形成。

They're called protoplanetary disks and they're so dense they absorb almost all the light from the stars forming inside them, so they're dark, and we see them in silhouette against the brighter gas of the nebula.

它们被称为原行星盘，密度非常大，几乎吸收了内部恒星发出的所有光线，所以它们很暗，我们在星云中明亮的气体中看到它们的轮廓。