I have the same question. But looking at the map, why would it be the first dark space between arms? It's just not that dark or empty either, and not a good candidate for 'nobody has been past it'. There is another rift beyond the next arm (the very faint one) where the stars really do thin out. Maybe we are looking too close to home?
"Keep going" didn't specify where you should stop![]()
It's not the first gap, but the second one. Around 10.000ly from Sol.