Good luck Ken!! You sound like you were really well prepared for it!!!
And mentioning the astronomy is a good thing!!! It shows you can 'think outside the box'. I went for a job interview with ANSTO and one of the questions i was asked was what is my greatest achievement besides academically... i couldnt think of anything but mentioned something more of an accomplishment.. having seen the shuttle launches here in australia. It basically got me the job cause i could think outside the box! So even if you don't think something is pertinant to an interview.. it may actually work in your favour and make u stand out from the crowd!
Hope you don't have to wait ages to find out! That is the sucky part!!
*crossed fingers*