@cstross @badastro ifs been like a decade since I read that .
I remember a Passage that had a THE STASIS station in the Precambrian and they were using a wormhole relay to do some kind of data processing or did I dream that…
Diamond Earth further up-when toward Terminus was intriguing .

So…and episode I caught yesterday had a stunning revelation that Major Chunks of Thea are still indivisible inside the earth and that they wrap the core like a pair of hands making it spin faster and giving us that protective magnetic field .

You know …there needs to be a radio program like How The Universe Works that is both exciting and engaging and tricks one into leaning updated facts about this Universe.

@cstross my understanding is that our planetary/star velocities form a helix/corkscrew path, with a 225 million-year galactic orbital year.

But presuming galaxy motion, we’ll not be exactly here & xkcd’s chart gives a second good reason we can’t just aim timing to return here a cycle earlier/later. 225M years either way probably ain’t hospitable.

But mars… interesting. I can’t see that spiral pair of paths spanning 1/3-1/2 of an AU to land there. But maybe something works: calculate travel timing to land somewhere useful.

Personally, I’d be stunned if time-travel position is locked; it’d mean position and motion have a non-relative frame of reference. Nothing in physics has that. So, perhaps position and velocity lock. E.g., travelers ‘coast’ along the path they were on, so no absolute frame of reference. That’d be *fun*.