A lot of people don't even know that being an astronomer is a real job - they consider it a hobby! Anybody can be an amateur astronomer; all you need is a good telescope and a map of the stars. To make a career out of it, though, you'll need a much stronger level of knowledge and equipment than that. Astronomers are scientists. They won't just know what they're looking at; they'll have a theory for why it looks the way it does, what it looked like billions of years ago, and what it might tell us about the universe we live in.
Astronomers will both undertake research themselves, and write detailed proposals to apply for funding for work that needs to be done. A Ph.D., a love of doing independent research and an understanding of scientific tools and their functions are all requirements for you to get to the top of this field. It's not rocket science - but it's not far away from it, either.