This solar system was dead. To be sure, most solar systems are dead – big hunks of gas and rocks which never even pretended to be anything but matter in motion – but this system was different. This system had been alive, once.
Preliminary estimates guessed that it would take decades to go through and catalogue all the debris. A few years would certainly be shaved off that workload by vigorous scavengers leaping at the chance to salvage spare metal and new alien technology. A few years would most likely be added by virtue of everything taking longer than predicted, even when this extra time was taken into account.
It didn’t matter. The past was very much the future, and there was much work to be done. A whole solar system’s worth of work, to be precise.
They might even find out what happened to these poor, forgotten souls.