I'll frequently leave Kittens Game running and come back to find several rare astronomical events have occurred. Once or twice they happen while I'm watching, and there's an "observe" button which awards me science. Presumably this button goes away after some period of time, which is why I never see it for the events that occur while I'm not watching.
How much time do I have between the noticing of a rare astronomical event and the loss of the capability to observe it?
From the code, in calendar.js:
var seconds = 60;
this.observeTimeout = setTimeout(dojo.hitch(this, observeTimeout), seconds * 1000);
Thus, you have sixty seconds to hit the button, lest the event pass you by.
Another event appearing in that window immediately ends the 60 seconds though (but still process the auto harvest chance if applicable). Observatories give a auto harvest chance, and later a research makes all events auto harvest.
There occurred a rare astronomical event at day 49, and the observe button disappeared at day 71, but from the other answer it seems to be unrelated to the days passed ingame.
