[2023] Is 90 and 270 degrees the new north-south axis for Mars, or is this a bug?

The latest update post on steam outlines the changes, being a celestial simulation.

Previously there was no simulation for the sun. It was just a light slapped onto the sky that rotated in one fixed direction. A rudimentary geocentric model.

Now we have a heliocentric model simulation using Kelpers laws of planetary motion. This means the position of the sun is based on your celestial bodies position in the solar system.

In addition, “north” in the game is an arbitrary direction that simply points towards “0,0,1” in the game world. It is like a grid north, it’s not necessarily where the body rotates around. It was never intended as a real value in the game and was added to the display simply as a convenience.

I believe the team have already changed the arbitrary direction to be +90 degrees on beta, which may come out as a hotfix.

Above a bit I provided some more explanation, but briefly the old implementation there was no model for compass direction, north was simply what the vector 0,0,1 was in the game.

However you should now find the arbitrary direction is more in line with what would be expected

To clarify; the movement of the sun simulation is fine. Just our visual description of the compass direction was completely arbitrary and not giving you a relevant direction. Which has been changed on the beta.