I had a moment of clarity in my current 5.20 campaign today, in which I realized that my empire was not alone in the universe.
I was happily going along when out of the blue my time increments shortened briefly. I was curious as to why, so turned on SM to check.
Turns out it was NPR versus NPR action... For about thirty seconds.
Actually, it was NPR versus precursor for the same length of time.
The Tsinghai empire, or whatever their name really is, was happily doing jump surveys when they stumbled upon HR 511.
This system seemed to have potentially colonizable planets and moons, to judge from the creation of several garrison units.
If the event log can be believed, the precursors detected the new populations quickly but only gradually grew hostile towards them, meanwhile remaining undetected themselves.
Sadly, the log is a bit confused. I gather some ship detection did eventually take place, but I'm not sure which ships did the detection, spacemaster mode being rather limited.
Suffice to say the precursors declared the Tsinghai hostile, fired missiles, and obliterated something like 12.6 million of them... All in around a minute.
One ground commander somehow survived the destruction of his unit, though how he'll make out on a radioactive chunk of rock I don't know.
Wow.