How can you find planets and stars billions of light years away from earth without anything inbetween to cover the sight?

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How can you find planets and stars billions of light years away from earth without anything inbetween to cover the sight?

In: Engineering

Space is very, very large and very, very, very empty. There is literally nothing out there at all, to several significant digits. Stars and planets occupy a terribly small fraction of the space in the visible universe. If there is something in the way, like a dust cloud, we can’t see the planet/star. But space is so empty that this seldom happens.

I think you’re asking how we can see far-away celestial bodies without anything blocking our view:
Space is really empty. Even in our solar system we can see every planet without another getting in the way (the only reason we can’t sometimes is because of the sun). Even the moon is way farther away than it seems.

On top of the other answers, when stars are behind other objects, we cannot see them because, well, they’re behind. We can only see those that don’t have something hiding them. I guess it’s some kind of survivorship bias.