Front Inside Cover: Young planetary nebula NGC 6302 (Butterfly nebula) with clear reddish-orange S-shaped gas from ionised iron atoms being blown out at high speeds. Picture credit: NASA/ESA, and J. Kastner

Back Cover: Double rainbow in the sky. Photo credit: https://www.sciencenewsforstudents.org/article/explainer-rainbows-fogbows-and-cousins.
. Alexander's band is seen as the dark shadow of unlit sky between the primary and secondary rainbows. (this is an inset)
. The figure showing the path of Sun's rays through a raindrop, forming a rainbow. Image credit Wikipedia (this is a small inset)