It's Mars!
It's a bit like the one I made for the Space Engine community, but that one is fictitious.
If anyone decides to use it, I hope you enjoy!
Oh, I've tested it as an icon, and even though the thumbnail image looks a bit wonky, it looks fine as an icon.
Thank you, and I'm glad it's working! I made a Jupiter one also, and you're welcome to keep it and swap them out from time to time if you want, maybe I'll make some more! Oh, and animated banners also work, just confirmed!