Is all of our universe… lit? Can you be hurtling through space and accidentally fly head first into a planet because oops you didn’t have your headlights on?
In: Physics
Think of it this way.
At our point in space, any light reaching us is point light from the star’s source. No “reflected” light is strong enough to reach us past a certain distance, just look how small Venus and Mars are in the sky.
We see things in deep space far away when they block light from the stars.
So to answer your question, if there is a star close enough to you, then everything is lit. If you are in deep space, then objects in space will cause dark spots as you move through. Theoretically, you could hit it if you were not paying attention.
Really good question because it requires multiple answers.
1) There’s a **LOT** of space in space. So it’s not likely to hit something except over really long periods of time (Billions of years).
[Astrophysicist Dr. Becky – Likelihood of Stars to Collide](https://youtu.be/_dZUNAZI2eg)
2) There is actually a lot of rogue planets, asteroids, dust, and other materials out there that are very dark and so would be hard to detect with our current technology until you crash into them.
[PBS Spacetime Dark Matter](https://youtu.be/z3rgl-_a5C0)
3) Technically, the vacuum of space is most likely the coldest thing in the universe at a chilly 2.73 K. So any real object made of atoms is warmer than that and so glows some light. This light can be infrared light that you might be familiar with from those glowing red heaters. You and I can’t see that light, but your skin can feel it as warmth and we have scientific sensors that can see it.
[Scishow Space Coolest Place in Outer Space](https://youtu.be/E5VTmc-QM6Q)
[PBS Spacetime Cosmic Microwave Background](https://youtu.be/3tCMd1ytvWg)
4) If you had a really bright headlight in front of your spacecraft, even if you were moving really fast up to high percentages of the speed of light (like 99%). The light you emit would still head away from you at the speed of light and so would illuminate objects ahead of you. Though you may not be able to correct your course in time to stop the crash.
[VSauce Would headlights work at the speed of light?](https://youtu.be/ACUuFg9Y9dY)
[PBS Spacetime Speed of Light](https://youtu.be/msVuCEs8Ydo)
Edit: Added video links
I feel like everyone who answered is hyper focused on a pretty poor understanding of what I assume your question was.
It doesn’t sound like you’re asking about the likelihood of “colliding with a planet.”
It sounds like you’re asking about whether or not you’d be able to see a planet, or asteroid, or anything else, regardless of what your interaction with it was going to be?
I don’t have the answer for you, but I’m just hoping that, if this is more of what you meant (it seems pretty obvious to me that this is what the actual question was), maybe people will be able to see this and understand the question better.
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