Many people aspire to be astronomers when they grow up, but since there are few professional astronomers in the world to talk to, it is often difficult to get any information on the career. Almost all professional astronomers (whether they are professors, researchers at universities, or technicians on telescopes) have a doctorate in astronomy, which usually means they went to college for around 4 years to get a physics or astronomy degree and then went to graduate school for 5-6 years to get a PhD. From there, it is a very competitive job market as all of the recently-graduated PhDs compete for limited spaces at universities.
However, if you enjoy astronomy, you don’t necessarily need to be a professional astronomer. There are plenty of resources for learning about astronomy (like this website!) that don’t require 10+ years of schooling and lots of physics and math. If you have questions about what it takes to be an astronomer, look through the answers below.
Don’t see your question in the archives below?
The path is different for everyone, but in general, most astronomers started out as high schoolers that were interested in science and math. Sometimes this was in astronomy specifically, but other times, people meander around various disciplines before landing on astronomy in particular.
In college, astronomers typically major in astronomy and physics, with a healthy side of math and computer science classes. This tends to be at a large research university, but this is not necessarily the case and many astronomers come from other backgrounds. In order to gain the skills important for succeeding in astronomy, it is important to do scientific research with a professor during your undergraduate education, usually over summers. The skills you develop, like coding, statistical analysis, and scientific literacy, are important for being a successful researcher so it is important to demonstrate that you possess them.
Following college, astronomers go to get their PhDs, typically from a different university than where they went to college. This consists of two years of taking classes (culminating in a master’s degree) followed by another 3-4 years of full-time research to finish the PhD. Along the way, their research is published in peer reviewed journals and compiled into a thesis. Unlike some fields, astronomers are usually paid during their graduate school and don’t have to pay tuition.
Most people who want to continue in the field then become a postdoctoral fellow (essentially a full-time researcher) at yet another university. These typically last a few years and some people have several different ones before they are finally hired as a professor or career researcher at some research institution.
This process from graduating high school to becoming a professor usually takes around 10-20 years and is by no means easy. Some people who decide that the long hours and difficult work are not worth continuing end up taking higher paying jobs in technology since the data analysis techniques used in astronomy are easily transferable to tech companies.
I think any astronomer would say that the best thing is learning new things about the Universe to try to make sense of it all. Astronomers have access to some of the largest and most impressive scientific instruments in the world and we can use them to see things that have never been seen before. The drive of making new discoveries is what everyone is always after. Astronomers often get to travel around the world to talk to others about their work as well.
However, that can sometimes create a culture of stress and competition among astronomers, which is something that many people do not enjoy. Research requires long hours and tight deadlines sometimes and that can lead to people going a bit crazy (there is plenty that can be said about toxic cultures within academia that I won’t go into here). Funding is sometimes precarious as well, so some people have to spend significant amounts of time writing proposals to fund themselves rather than doing fun things.
- You get to do something that basically everyone think is cool: Space is interesting to almost everyone on some level, and a knowledge of what is going on in the Universe can almost always wow people in conversation. Whether you’re talking to friends about some astronomical event that just happened or whether you’re telling someone how the Universe works, people will usually think you’re cool
- You spend your time investigating things you’re interested in: If your passion is astronomy, then being an astronomer gives you the opportunity to do it full-time and devote yourself to your work. I like not working for a company trying to make a profit but rather working for humanity trying to increase our collective knowledge.
- You get to teach others about why it’s cool: Most full-time astronomers are also professors, so they teach classes at universities to introduce people to astronomy or dive deeper into specific advanced topics. Most universities also have some sort of public outreach program where students and professors go out into the community or into schools to teach about what they do. Either way, you spread the passion for astronomy
- You get to go to lots of places and meet lots of people: Astronomy is a very international field and people often collaborate with people from all over the world. People often present their results at conferences around the world as well, allowing you to see many places
- You have to go through a lot of school to get there: Being a professional astronomer requires a college degree and a PhD, and with 4 years for college and 5-6 years of PhD, you typically are in your late 20s at the earliest before you’re applying for jobs and really getting started with your career. At least you get paid for the time you are in your PhD (unlike in college), although it’s not as much as something in private industry
- Academic jobs are hard to find: Astronomy professor jobs are hard to get, which usually means that you have to bounce around various universities for several years before you find something permanent. These jobs are usually not as high-paying as some of the other jobs you might be qualified to get at a tech company or something also. Most astronomers don’t get permanent professorships until their 30s.
- It can be stressful: There are often lots of external pressures on astronomers to push themselves hard to do their work. Deadlines, job requirements, and competition mean that sometimes the hours can be long, and since work is not really as contained as some other jobs, it’s not as easy to just “go home at 5:00 and be done for the day.” Academic culture can sometimes be toxic and have bad power dynamics as well.
Jobs in astronomy are usually scarce because there are more students than professors, so as you get higher in the field, jobs become more scarce. At each stage, people tend to leave the field so only a fraction continue upwards. For instance, there are around 150 astronomy PhDs given per year, but only about 60-75 professor positions that open up. Some people leave the field and go to work for a tech company since astronomy teaches you a lot of programming and data analysis skills that are useful elsewhere.
Most professional astronomers are associated with some university, either as a professor or as a researcher. You start getting paid for astronomy when you are a PhD student and from there, typically people earn their PhDs and then go to another university to be a researcher for a few years before applying to be a professor somewhere. There are also positions at non-university institutions like observatories or governmental organizations like NASA that need astronomers on staff.
One of the reasons astronomy jobs are so scarce is because professor jobs are usually given for life. Once a professor is hired, they usually stay with the same institution until they retire, which is often about 40 years. Before you land a permanent professor position, though, you bounce around different institutions every 2-5 years as a graduate student and researcher.
Speaking from my experience as a physics major in undergrad and a current astronomy PhD student, astronomy does require a lot of physics and math. Depending on where you are in your educational career, it is probably not too late to get started though. If you are still in high school, then you’re totally fine, just make sure you learn the math and physics you can while you’re there to get a good background. If you’re already in college, then just take the calculus classes that are necessary to start in on the physics track and work along to complete whatever degree you want to earn. You will probably have to take at least vector calculus, linear algebra, differential equations, and Fourier transforms in math and modern physics, electricity & magnetism, classical mechanics, and special relativity in physics to have a solid background. A good knowledge of statistics and programming is also useful since those are the tools necessary for astronomy research nowadays.
- Work your way through an introductory astronomy textbook: I would recommend going to the webpage for a university intro astronomy class and seeing what textbook they use and then finding that book at a library or online and reading through it. These books typically don’t require any background other than some math and should provide a good survey of the subject at a more technical level than popular science books and TV shows. For instance, here is the book used at UC Santa Cruz where I am.
- Work your way through a more advanced book: If you want something more technical, this textbook by Carroll & Ostlie is basically a standard for undergraduate astronomy programs. It goes through a similar set of information as you would find in one of the intro books from above but in much greater detail. A full understanding will require some sophomore/junior level physics and math but if you can get through it, you will have a pretty good grasp of undergraduate astronomy.
- Go through course syllabi that professors post online: The most thorough (and most labor intensive) way to do this would be to pick a large university of your choice, look at the courses they require for a degree on their website, and go the syllabus of each course. Professors usually have a personal website where they post all of their requirements for the course (including the textbook), slides, homework assignments, etc. If you find such websites for each required course, you can do all of it on your own (albeit with a lot of effort). For example, here is a website for an introductory astronomy class at UCSC and here is the website for a more advanced class on stars. If you do a good job of choosing classes to “take” and study for a few years, you should be able to get a good education.
Assuming you're talking about a full astronomy major rather than just one class, I can tell you that modern astronomy relies a lot on physics and computing knowledge. Most astronomers have a good physics background (my undergraduate degree is just in physics, not in astronomy), so many of the assessments are long "solve this physics problem" type of tests that are frequently very difficult.
The design of the tests obviously vary by subject matter and professor, so sometimes they are taken in class, sometimes they are given like homework assignments, and sometimes they are more like projects. If you are taking a class that is more about computing techniques and data analysis, a large project may be more appropriate than a sit down pen and paper test, so professors are flexible. If you are taking a physics lab, then you are usually assessed based off of your lab reports.
In order to get into a PhD program, most departments require applicants to take the Physics GRE, a standardized test that spans the entirety of the physics major. This test has a reputation for being difficult and for requiring you to work quickly, so people often study for months in advance. You also have to take the normal GRE, which is just like the SAT but less militaristic. As a PhD student, the tests are usually less frequent, but there is usually some test of your knowledge of the classes you take in your first couple of years and a test that evaluates your knowledge of your anticipated thesis topic, both of which must be passed before working on your thesis.
I know all of this sounds super intimidating (there are a lot of tests in academia) but if you enjoy the material and put effort into learning it, they're not so bad, and you may even start seeing them as useful tools for guiding your learning (results may vary depending on how nice or well-meaning your professor is). At this stage in my academic career, I respect a well-designed test because even if it is difficult, it may still encourage me to think about things in a new way or to put different ideas together. Hopefully all of this answers your question and let me know if you need more information.
Almost all graduate schools in astronomy in the US don’t offer a standalone master’s degree, they just admit you straight from bachelor’s to PhD and give you a master’s after the first couple of years. People usually only end up leaving programs before their PhD if they choose to leave the field entirely, and even at research institutions that are not affiliated with universities (like NASA, the Space Telescope Science Institute, etc.), basically everyone has a PhD. There are other fields that you can get a master’s degree in that will let you work adjacent to astronomers, like data science, robotics, engineering, or computer science though, so if the amount of schooling is very important to you, you might want to consider those.