Nerthus And New Mars

"The Pirate."

Nerthus is a much-mentioned planet. See Nerthus And Thunderhead. By contrast, we know very little of any other planets in Poul Anderson's Psychotechnic History. We are told a few names:

Highsky
David's Landing
Oasis
New Mars
Vanaheim
Reardon's

Trevelyan works with a Reardonite (nonhuman) and meets a New Martian (human). Because there are not enough unclaimed humanly habitable planets, "...marginal ones get settled too." (p. 140) New Mars is one. Trevelyan imagines "...scarring poverty..." (ibid.) in the background of the New Martian woman, Faustina. And that is all that we learn about New Mars.

I have encountered the term "New Mars" before:

one DC superhero was a Martian who had teleported to Earth;

later, he rejoined his people who meanwhile had colonized an extra-solar planet, "New Mars," thus retroactively acknowledging and incorporating the fact that Mars is not inhabited;

later still, his origin story became that he not teleported from present Mars but time traveled from past Mars.

(Science fictional rationales can be ingenious.)