Dear Colleagues:
The current discussion between Richard Branson and Jeff Bezos about where space begins may lead to questions from students, colleagues and friends about this issue. A few years ago I created an activity, called "How High Up is Space," for the Astronomical Society of the Pacific, on this topic, and it is available free at:
https://astrosociety.org/file_download/inline/74e02a72-a5c6-48d3-a498-d87732a44388
Andrew Fraknoi
(Former Executive Director, Astronomical Society of the Pacific)