Free: Download Neil deGrasse Tyson’s Short Course, The Inexplicable Universe, in Audio or Video Format | Open Culture
For now, The Great Courses will let you access Tyson’s Great Course for free, including all of its downloadable audio and video lectures, as long as you make an account at their site — a process which, we can report, entails only a reasonable hassle factor.

Camp Google | Camp.WithGoogle.com
Camp Google is a free summer camp that gets kids learning through fun, interactive science activities and adventures. Led by experts, the activities have been designed to encourage kids to ask questions, setting them on a lifelong journey of exploration and discovery. Everyone is welcome, and you can jump in anytime.