Reddit mentions of The Cosmic Perspective (8th Edition)

Excellent! Thanks for the addition to my answer. I've never heard of Bennett's book. I'll have to order it myself 😊

Edit: Here's a link to Bennett's book for the OP:

The Cosmic Perspective (8th Edition) https://www.amazon.com/dp/0134059069/ref=cm_sw_r_cp_apa_XuGWBb1GNT7E8

Now that I see the cover, I actually recognize it from some undergrad courses for which I was TA. Great book!

Also not a teacher, though I just wanted to point out that the widely-used textbook for first year astronomy 'science for non-science majors' courses, The Cosmic Perspective, while pricey, is a great resource on which to base a two semester course. It has more in it than you'll need, so you can pick and choose chapters to expand into classroom content. It's almost entirely word-based to keep math out of it, so you can set the math level to whatever grade you're teaching. It covers human endeavours to observe the universe from ancient times onward, and astronomy from the Solar System to the edge of the observable universe.

I know someone who taught astronomy as a single unit in their grade 9 science class. Though not a full course in itself, if it would help I can ask if they still have their lesson plans and notes for the unit.

Bennet, The Cosmic Perspective (8th Edition) ISBN 0134059069

Amazon Link