I write science fiction, and truth be told, and I think the space opera form has life in it yet. While my last story was set on Mars and didn't have a lot of interplanetary travel, this project does. Mostly because I want to cover a long period of time in the stories that I'm writing now, so that we can see characters relate to histories. So I have characters on space ships.
One thing that I have yet to do, is create some sort of FTL (faster-than-light) construct in the stories, and while I'm not hyper vigilant about making sure that planets are actually going to be where they are in relation to each other when I say they are, I've built transit times into my plots and stuff like that, so that there's at least some sense of a "price" for technologies that seem too good to be true. And I think in some ways this connects to some sort of notion of constrained creativity and particularly in fiction this is what makes stories interesting
So, in pursuit of making this work I occasionally find myself looking up orbital mechanics and interplanetary transit systems, to figure out how to get ships and planets to be in roughly the same place at the same time. There's only a little bit of this, in the current book thankfully: most of the story takes place on ships bound out of the solar system and on Titan, Saturn's largest moon. But at the moment I'm following a ship that's making it's way to Titan, with a brief detour to Mars. So I once again find myself trying to figure out Martian orbital dynamics and distances. Sigh.
This website about Martian Orbits is quite helpful.
Also, for those of you playing along at home, I think--think here--that an object that was .25 of a martian year behind mars in orbit would be about 17 light minutes away from Mars. This is between Mars and the L4 (or 5 if mars is ahead) Lagrarian points, which are, despite being farther away only 12 minutes away. (.25 of a year, is 45 degrees ahead/behind mars, the L4/5 points are 60 degrees ahead/behind. I'm figuring that the Mars Orbit, at 1.5 AU, to Earths 1 AU has a radius of 12 light minutes, or 134123326 miles.)
This ignores the fact that the orbits are all elliptical, and the effect of gravity on light/radio waves, which exists, surely, but not I think to a degree great enough to affect the truthfulness of a character that says "The message is about 20 minutes old."
I wonder if you can get a job doing something with rudimentary orbital mechanics with an undergraduate degree in psychology and no college level math. Sigh. Guess I better stick to writing.
Hope your turkey preparations are going well.