system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What is a Nebula, and why is it not absorbed into some stronger source of gravity?
gpt
A nebula is a cloud of dust that is often the early stages of a solar system forming.  If conditions are right it will eventually collapse on itself and form a star and planets.  If there is a strong source of gravity nearby, then yes it would get drawn into that, but space is huge and mostly empty.  There's usually not anything close enough to draw it away.