A bit of guidance please?

Hey, I'm Melisa and only 16 yet I am pretty definite about my goals for University and future life. I have always persevered to study medicine to then specialise in paediatric haematology-oncology.
However, I have an undying passion for the galaxy and the physics and theories behind it all. I was figuring that once I completed my Masters - Professors, I would like to go back to Uni and do an astronomy/astrobiology course. I want some ideas/guidance as to if this is realistic or nearly impossible to study for so many years of my life and then go on and specialise in a completely new field.
Some replies would be nice Thanks for your time guys.

I think you need to decide what you're interested in doing for a living, not just what you're interested in as a person. It's okay to still be unsure at this stage btw, you've got a good while left to decide.

Being a doctor is a full time commitment - there's no point going to medical school, qualifying as a doctor, specialising as a paediatrician (that's about 15 years of education and training in the UK btw), and then chucking it all in and going off to study and work in astronomy. That would be a very inefficient and expensive use of your time. If you want to work in astronomy, just do an astronomy degree.

I think it would be worth taking some time to decide whether you're more interested in being a doctor or working in a field to do with astronomy/physics. If you decide you're more interested in medicine, you can still maintain an interest in astronomy btw, even if you don't have a degree in it.

Just as an aside...make sure you're interested in medicine generally - not just paediatric oncology. That's a very specialised field, and one you're not likely to properly encounter until the end of your paediatrics specialty training.

Firstly, thank you for your detailed reply.

As you mentioned I genuinely have an interest in medicine so it would probably be the field I pursue (fingers crossed) however, when it comes to the astronomy/astrobiology side of things, I really feel this may remain as a hobby for me.
It not only seems unrealistic coming from the underprivileged background I do but my de-motivation stems from the pressures of family preferences.

I was wondering if you had any idea as to what you would do?

I think I'd consider it from a career perspective. University is only for a few years after all, but having a job is for the majority of your life. So I'd think about it as whether I'd prefer to be a doctor or an astronomer, rather than whether I'd prefer doing a medical degree or an astronomy degree. Getting some work experience in a hospital might help you decide if being a doctor is for you. If you decide it isn't, that's fine; I doubt you'd have trouble finding a job with a physics related degree like astronomy.

Family preferences are irrelevant, it's your life after all

go where your heart leads you
but you will need money coming in, reality of life

I think I'd consider it from a career perspective. University is only for a few years after all, but having a job is for the majority of your life. So I'd think about it as whether I'd prefer to be a doctor or an astronomer, rather than whether I'd prefer doing a medical degree or an astronomy degree. Getting some work experience in a hospital might help you decide if being a doctor is for you. If you decide it isn't, that's fine; I doubt you'd have trouble finding a job with a physics related degree like astronomy.

Family preferences are irrelevant, it's your life after all

I think this is the best advice you'll get, OP! The first thing to do is find out if you really want to work as a doctor for the rest of your life: if so, medicine is for you!

Astronomy is totally something you could learn more about as a hobby, and a lifestyle in medicine is totally conducive with other interests. I've always been kind of interested in physics and throughout first year I could still do a lot of extra reading (and I eventually lost that interest ). Nowadays, I have a degree in sports science (where I got to study lots of biomechanics and learn some new physics), and read a lot about history and other languages. I think it's always good to have other interests like you do.

Yeah it will most definitely remain as a lifelong hobby but it seems unrealistic to aspire to work for space station organisations such as NASA etc.