Garmaine Staff asked 2 years ago
How can I find points of latitude and longitude on Mars that fall on the terminator (day/night line) on a specific date, for example 1976-07-24T10:35:26Z as mentioned in this answer to Which Viking-1 orbiter photo is this? When was it taken and what part of Mars is shown?
I know that Horizons has rotational information of the planets and so I could pick points on it and observe the Sun and get its altitude above/below the horizon and through interpolation I could find the terminator, but perhaps there's an easier way.
Are there tables of epochs of say local noon at zero longitude? That could be interpolated smoothly and then just using the direction of Mars' axis and it's location relative to the Sun I could use geometry to get the terminator. Do such tables exist? Are there others ways to do this as well?