Hi All,
I think you shouldn't be too negative about the prospects of being accepted or your chance of success. Historically, mature aged students do very well. While they may not be as fast as a teenager they more than make up for this in motivation, organisation and application. [I remember some kids complaining that a certain prac. assignment was boring - and it was - but I reflected to myself that having stood in one place for 8hrs sorting bananas into different sizes this was a doddle.]
Unis run these courses to make money. Certainly the academics involved may want to spread astronomical education but the only way to get the course past management is if it will bring in $$$. So there is motivation to get students into the course. Now, if a course has a too high failure rate there will be questions asked, so they can't just admit anyone but there is a definite motivation to find reasons to admit applicants. I don't know why the admin-drones who answer inquiries come across so negative, possibly ass-covering, but I doubt that they make the decisions. In my experience, that is done by academics.
If I was accessing a mature-age applicant I wouldn't so much look at how long ago they finished their last education as what they have been doing since. [I think that flying A380s would qualify as keeping the brain active.] I'd also be interested to know that they had a long-standing active interest in astronomy, especially if it came with a portfolio of astro-images. Or perhaps you've built a scope or given talks to your astronomy club or WEA or whatever. If, heaven forbid, anyone is reject by some alogorithm, find out who can override that decision and contact them - politely.
Masters degrees come in all sorts for many different purposes. There are research Masters which may be used to gain admission to a PhD. In the Aust system most students would gain admission to a PhD by getting first class honours on their undergrad degree but if they don't achieve that they would have to attempt to gain admission via a Masters. There are also more vocational coursework masters which extend or augment previous education. I know an 'electrician' (not sure of his qualification but it above trade level) who worked for the steel works and he did a masters in maintenance planning. Apparently industry had identified a need and the Faculty of Commerce was happy to oblige with a (full-fee) course. SEALS at Wollongong runs course in GIS aimed at people outside earth science who need these skills (eg transport and logistics). Then of course, there are the general interest courses for someone who has shown they can survive an undergrad course (or maybe even show equivalent experience). These may not even be able to lead to a job. For instance, the maths might be simplified to the point that you couldn't work in astronomy. But vege maths may be just right for you.
Please, if you have a passion for education don't be put off at the first hurdle.
