I have been doing MOOCs regularly with Coursera, Futurelearn and Edx and mention a few below that I did recently.
But, please note, the platforms for these three leaders have important differences so if you have experience with one then don't assume the others are the same. Also then content differs with Edx have more academic courses and Futurelearn more for the casual learner. Coursera has some of both.
Modelling climate change
Currently doing a course called Religous Literacy
Strategies for successful Aging
Monitoring climate from space
Exlporing our oceans
Critical Thinking in Global Challenges
The Science of the Solar System
Planet Earth...and You!
Energy and the Earth