interstellar

Rather, they are dark because of interstellar dust that hides the stars behind it.

相反，它们之所以是黑暗的，是因为星际尘埃将恒星隐藏在它的后面。

The interstellar material, rather like terrestrial clouds, comes in all shapes and sizes.

星际物质很像地球上的云，形状大小各异。

Optical astronomy is most directly affected, for although interstellar gas is perfectly transparent, the dust is not.

光学天文学受到最直接的影响，因为虽然星际气体是完全透明的，但尘埃却不是。