A distant planet whose human population was brought there from World War III-era Earth by the Red Angel, later revealed to be Gabrielle Burnham.
Terralysium is the planet Discovery reaches by spore drive in New Eden while following one of the mysterious signals. Christopher Pike and Michael Burnham find a previously unknown human community whose ancestors left Earth during World War III and who practice a religion blending several faiths. A helmet camera recording shows the Red Angel transporting the founders from Earth, and Sylvia Tilly helps avert an extinction-level radiation shower.
In Perpetual Infinity, Gabrielle Burnham explains that she tethered herself to the planet and moved humans there to test whether she could change history.