Consider that the Earth is just a giant cosmic dust bunny—a big bundle of debris amassed from exploded stars. We Earthlings are essentially just little clumps of stardust, too, albeit with very complex chemistry.
And because outer space is a very dusty place, that makes things very difficult for astronomers and astrophysicists who are trying to peer farther across the universe or deep into the center of our own galaxy to learn more about their structure, formation and evolution.