www.bradyharan.com - Brady Haran has two(i think) channels devoted to space, sixty symbols and deepskyvideos. his educational channels are probably one of the most amazing things in the world.
Anton Petrov - this channel is more looking at recent news articles and studies and explaining them in an accessible manner, but due to the daily nature of videos is limited in scope.
if youre instead looking for more of a formal study content, cant help you