Hopefully the question makes sense. But it seems like we are always getting such great photos of these objects. You would think that one day you may be able to see a galaxy; while the next it may be completely obstructed by another object that is closer to earth but still thousands to millions of light years away.
In: Planetary Science
Space is huge. You could fit all planets from our solar system between the Earth and the moon. All at once. Space is huge. The junk is small.
The same reason a flashlight doesn’t blink from the particles of dust moving through the air. Even over large distances, they’re too small to make a visible difference.
In the scale of space. Debris are so small I imagine they’d make almost no impact on light travel. Planets etc however if perfectly aligned to completely cover a start would block out light.
Space is extremely empty. The average density of the universe is 1 hydrogen atom per 3 cubic meters. Outside of small regions of dense gas (which do block our view of stars behind them) there’s basically nothing there to get in the way.
The short answer to this is that space is almost entirely empty space. Like mind bogglingly empty. When you look up in the sky it looks packed with stars, but in reality the vast distances of empty space between them are so immense it’s hard for our minds to comprehend. The time scale for one object to move enough to obscure another that we are looking at is likely to be millennia at the smallest.
That said, there are things like nebula, clouds of dust and gas, that can block our view of things. In those cases we use telescopes that operate in different wavelengths, like infrared, to see through them.
Space is pretty much just empty space. There isn’t a whole lot of anything going on for most of it. Just as an example the asteroid belt is a fairly dense region of space. Dense enough to get it’s own name specifically because it’s the most likely place to find asteroids. Asteroids in the belt are also hundreds of thousands of miles apart from each other. If you you where to fly through it in a rocket, there is a good chance you don’t see anything unless you where flying to a specific asteroid. The rest of space is even emptier. Just void.
As others have said, space is just way bigger and emptier than you’re thinking. As example to make it more intuitive, consider this question:
“Shouldn’t the light from the ceiling light in your room right now be blinking due to the thousands of dust particles between you and the bulb?” or “should the illumination under a streetlight on the roadside be blinking due to all the debris in the air outside?”
Hopefully you can “feel” that the answer is “no of course not, because the debris is too small and too few compared to how big the light source is and its brightness.”
Well your question has the same answer, and for the same reasons. Even for far away stars, the debris between us and the star is too small and to few to obstruct the light by any meaningful amount. It’s like the dust between you and the lamp across the room.
You’re vastly underestimating how empty space is. And a small piece of debris isn’t going to do anything measurable. It takes an immensely sensitive telescope pointed at a star to detect a miniscule dip in light *from an entire planet* passing in front of it. See the Kepler mission.
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