The Purple Twilight, a 1948 novel written by Pelham Groom

Here’s a little-known science fiction/fantasy novel about Mars that’s new to me: The Purple Twilight, by Pelham Groom (London: T. Werner Laurie, Ltd., 1948). A synopsis of the novel, compiled from several descriptions provided by booksellers on AbeBooks: Debonair adventurer Peter Mohune travels by rocket from a satellite aerodrome to an inhabited Mars, where he is shown visions of Earth’s past, including a culturally-rich Atlantis that was destroyed by atomic energy and cosmic rays. Apparently, The Purple Twilight is a "cautionary tale concerning nuclear arms race."