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
You know how in a lot of sci fi movies they pass through an asteroid field and the pilot has to maneuver the spaceship expertly to avoid colliding with the Asteroids?
In real life, you can pretty much go through the Asteroid belt between Mars and Jupiter with your eyes closed and won’t hit anything at all. In fact, you probably won’t even _see_ an Asteroid unless you look through a nice telescope.
Space is empty. _Really_ empty.
Another way to think of it this: In about 4 billion years, Andromeda and Milky Way will collide with each other. Two galaxies with 500billion – 1 trillion stars _each_. The fascinating part? Even after the galaxies collide, pretty much none of the individual stars will hit _anything at all_.
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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