Space debris is a serious threat that only grows as the number of launches and satellites rises exponentially. If you're curious about the source, scale, and history of the problem, you could do a lot worse than this 101 article at Built In.

Author Jeff Rumage gives an accurate picture of the space debris (or "space junk") situation, not just summarizing what's out there but speaking to people actively working in the field — among them Aerospace's Greg Henning.

Henning is a lead at the Center for Orbital and Reentry Debris Studies, where they've developed ADEPT, the Aerospace Debris Environment Projection Tool. This sophisticated modeling and simulation system predicts how different approaches could affect debris accumulation and effects on satellites.

With satellites going up at rates unimaginable a decade ago and thousands of debris objects entering and leaving orbit, however, he suggests we should look forward before we attempt to remediate the mistakes of the past (such as anti-satellite weapon testing).

“Given how difficult this problem is to solve, focusing on mitigation and remediation of large debris objects still appears to be the most effective approach we have right now,” Henning told Built In. “If you can prevent the creation of small debris in the first place, we may never have to figure out how to clean them up.”

It's a complex problem with a lot of angles to cover, though, so if you want to know more, you can read the full article here.