What a delightful little tale! The narrative style (written as a letter, so little dialogue and more description) reminds me of William Hope Hodgson, as does the blend of science and the fantastical. I also enjoy the subtle worldbuilding, and while reading I felt immersed without being dictated to.
In case helpful to anyone (this is probably noted elsewhere), the anthology that contains this story has a cheap kindle version on amazon (~8 bucks).
https://www.amazon.com/gp/product/1786641828?pf_rd_p=ab873d20-a0ca-439b-ac45-cd78f07a84d8&pf_rd_r=ACP4MAME3ZM905PVT6VG
Now to my reading chamber!