funny, i actually concluded that indeed it's the scorpionaut ship too where the urns drop from, and wanted to be sure about it so taking some time to investigate, then came back to post and see somebody else posted the same
but yes, it is definately the scorpionaut that drops it, and it's at the same exact moment. you can see the population flock towards the central opening. perhaps some sort of refuge place for them to think they're safe there?