It's a rare (but less rare than it used to be) event for it to show up in your farm. Something will happen to it in a few days and apparently that is supposed to trigger another small event elsewhere on the map (Bus Stop I think?) that you need to be observant to see. I got the Strange Capsule for the first time on my current save and the thing happened to it a few days later, but I have still to see the following event on the map as it takes being observant.
And I am not. I focus on one thing and all else is trivial fluff. Sometimes I can keep upwards of 1.1 things in my mind but they usually end up looking like Vena's true form from the Star Trek pilot. I rarely notice subtle things that are given as clues. For all the stuff on Ginger Island that you're supposed to infer from hints, I've had a real problem with those. And the parrots taunt me, but that's another issue.
I wish you better luck and observing skills than I have.