Now that many workplaces offer telecommuting and flexible scheduling options for their employees, it seems natural that universities have followed suit to enable students to take classes without actually having to be on campus.

But colleges and universities aren’t the only ones offering online classes. A number of companies are providing platforms for users to take and teach a variety of courses. Skillshare, for example, offers classes taught by “everyday creators" on a variety of off-the-beaten path subjects for personal and professional development, such as knitting, pickling, t-shirt design, and Facebook marketing. You can even take a class called Teach Online: How To Create & Launch Your First Best-Selling Course, and use the platform to transition from student to teacher on the very same site.

For a sense of the shifting landscape of online learning, here is a list of emerging trends in online courses, as well as a selection of classes you can take from colleges and other organizations.

Astronomy

Space is, of course, a great mystery. Naturally, something that we know so little about lends itself to fierce class discussions and fodder for online courses.

Believe it or not, you can take classes with the Planetary Society, a non-profit run by Bill Nye (that’s the Science Guy, to all of you born in the 1980s). Classes consist of a set of pre-recorded lectures by California State University Dominguez Hills professors, and you can take a quiz to receive a certificate of achievement.

Looking for something a little more intense? Take a 9-week course with Caltech on Galaxies and Cosmology, and learn a little something about the interstellar medium.

Coding

Coding is applicable in nearly every industry. Free courses are a great way to learn a skill that will give you a competitive advantage. Meredith Ruble, CFO of The Noodle Companies.

Coding certifications are all the rage, with MOOC offerings from Khan Academy, Udacity, and Hack Reactor, to name a few.

While online coding classes and lessons have been around for some time, the range of options that now exists is remarkable. You can follow over 100 free lectures (thanks to funding from Sequoia Capital), such as Machine Learning and Programming Paradigms, from Stanford’s Engineering Everywhere project.

There are also a range of options specifically for women and girls. Hackbright Academy, Ada Developers Academy, and Black Girls Code are looking to support gender and racial diversity in a male-dominated career space.

Climate Change and Sustainability

It’s difficult to deny that climate change is affecting all aspects of our lives, but there are plenty of classes you can take to learn about the issue.

Under the umbrella of its Global Studies program, NYU offers a course called Renewable Energy in the Age of Cheaper Oil, which touches on economics, sustainability, and technology. Or, if it’s the question of how humans impact the earth’s climate, you may also look into Global Warming I: The Science and Modeling of Climate Change through the University of Chicago.

Tufts University offers a course on The Biology of Water and Health-Sustainable Intervention. The drought in California is a recent example of natural devastation in the U.S., but a lack of access to safe water is a major, worldwide crisis. If you’re curious about the science behind water sustainability, as well as the contentious issues of hydrofracking and water privatization, you can enroll now for a future class (dates to be announced).

Cybersecurity, Online Privacy, and Hacking

Facebook’s constant privacy setting updates got you all in a tizzy? You’re not alone.

If you hold a BA in Computer Science and are looking to deepen your knowledge of cybersecurity and online privacy, MIT has a class called Cybersecurity: Technology, Application, and Policy for those interested in developing their technical skills further and gaining new knowledge of the cybersecurity landscape.

Stanford offers an Advanced Computer Science Certificate Program, the focus of which is cybersecurity and building secure infrastructures. Southern University of New Hampshire offers a Graduate Cyber Security Certificate, with class topics ranging from organized crime to private sector justice.

Psychology, Wellness, and Mental Health

Just like outer space, the brain is something we still know very little about. All those neurons, synapses, dendrites, and sheaths enable us to make decisions and develop our unique personalities, and scientists are keen to understand the many neurological disorders that affect the population but often have no cure or known cause.

The National Academy of Neuropsychology — which has been approved by the American Psychological Association to sponsor continuing education for psychologists — offers courses in neuroanatomy, psychopharmacology, and behavioral and cognitive neurology.

On a happier note, UC Berkeley offers a course in, well, happiness. “The Science of Happiness." introduces students to positive psychology and evidence-based strategies for fostering their own happiness.

UMass Boston also offers online courses in psychology, counseling, and substance abuse. Its course on Social Attitudes & Public Opinion covers the interesting topic of how our family, education, and the media influence our behavior.

These are just five areas out of many in which you can take an online class. The options really are, as they say, endless. Whether you’re looking to learn a new skill, change your career, or indulge a burning interest, the course selection is vast, and classes themselves are shockingly comprehensive. Try something new; you never know how much you may enjoy this way of learning.

Interested in online learning? Use Noodle to search for online classes you’re thinking about taking.