Eli5 How do we document dark space? (chunks of space that look like the void)

Question

I found it weird how we came to document areas in space where there is very little of stellar bodies. How do we figure out what’s in there and avoid any kind of rouge dark planets of black holes, or anything that could disrupt the mission of a deep space satélite? (There wasn’t a space tag so imma put it in planetary science)

In: 3

Answer 1

as of right now we only have incoming light to study deep space. one of our oldest and fastest moving probes only just recently “left” the solar system after years in space