The number of satellites is less than the number of oceangoing ships, but satellites are on track to be ahead in the next decade or so.
Then if you start counting every single piece of debris a satellite can run into, you're looking at millions of objects. Unlike ships, the debris (and even many satellites) doesn't have anyone "on watch" and there's no way to steer out of the way at the last minute. Because of how orbits work you can't really organize traffic into "shipping lanes".
If you want to do the math yourself, NORAD publishes satellite orbital parameters, which can be used to look for potential conjunctions. You can also sign up for an account at https://www.space-track.org to see the Space Force's data, or CelesTrak for something similar that isn't login-walled (https://celestrak.org/SOCRATES/). The tl;dr is that it's not rare for 2 satellites (or a satellite+debris) to have a 1 in 10,000 chance of crashing into each other. As more and more satellites go up and more and more "1 in 10,000" events happen on a daily basis, more conjunctions will occur. Each conjunction can create thousands of pieces of debris, which exacerbates the problem- nowadays I think ~30% of all debris in LEO comes from China's 2007 ASAT test.
Then if you start counting every single piece of debris a satellite can run into, you're looking at millions of objects. Unlike ships, the debris (and even many satellites) doesn't have anyone "on watch" and there's no way to steer out of the way at the last minute. Because of how orbits work you can't really organize traffic into "shipping lanes".
If you want to do the math yourself, NORAD publishes satellite orbital parameters, which can be used to look for potential conjunctions. You can also sign up for an account at https://www.space-track.org to see the Space Force's data, or CelesTrak for something similar that isn't login-walled (https://celestrak.org/SOCRATES/). The tl;dr is that it's not rare for 2 satellites (or a satellite+debris) to have a 1 in 10,000 chance of crashing into each other. As more and more satellites go up and more and more "1 in 10,000" events happen on a daily basis, more conjunctions will occur. Each conjunction can create thousands of pieces of debris, which exacerbates the problem- nowadays I think ~30% of all debris in LEO comes from China's 2007 ASAT test.