Space ponies must be found by searching your planets for Artifacts iirc, right? On a game I played today I found them by searching for artifacts on an asteroid and then cancelling the upgrade to search for artifacts before it finished. Probably 10-20 seconds after that I got it.
I have no clue if this would work for other artifacts/planet bonuses or not as that's the only time I cancelled that upgrade.
I have a screenshot of it too, but photobucket and steam are not behaving right now. Might try posting it later.