Behind the Screens – Prep With Me: Musings on Planets

With the official release of Starfinder fast approaching, I thought it would be an opportune time to start prepping some homebrew material for my group. As is my custom, these brainstorm sessions get turned into Prep With Me articles so y’all can follow along with my process and take a peek inside my head and behind the screens as it were.

In my last Starfinder musings, I talk a bit about how a GM can keep up with a narrative that crosses the vast expanses of space and time. The main thrust is that because we are telling a story about the PCs, the narrative follows the them. It matters less where things are happening so long as those events are engaging your players. While I stand by that advice, I wanted to also address that challenge with a different approach – by creating an interesting backdrop for adventures in a galactic/sci-fi setting. In essence, I am literally world-building.

I’ve been kicking an idea around in my head for a little while, a planet with an elliptical orbit, that is to say a planet whose path around a star takes them closer or farther from that star depending upon the point in that journey. So instead of travelling around its star in a circular fashion, it’s path is more of a squished-circle.

Planets with elliptical orbits are nothing new in fantasy. Pathfinder’s own Triaxus for example, follows an extreme elliptical orbit that causes drastic changes in climate. It’s been theorized that Game of Throne’s own world might follow an extreme elliptical orbit, which would account for its incredibly long seasons. In reality, our own Earth also follows a slight elliptical orbit, with our distance from the sun being anywhere from 91 to 94 million miles depending on the time of year.

As a quick aside, the first great lesson of world-building is that nothing is new and chances are someone somewhere has an idea that’s similar to yours but better developed. And is a published work. And has tens of millions of fans world wide…

But that doesn’t mean your idea isn’t a good one. And if you can somehow make it your own you can run with it and have a great time.

The nature of planetary orbits and rotations are fascinating. To use Earth as an example again, we occupy a very narrow ring around the sun called the circumstellar habitable zone within which the perfect conditions for liquid water for our biosphere exist as we know it. Further, the whole reason we have seasons on Earth is because of our axial tilt, that 23.5 degree angle relative to the our plane of orbit as we travel the sun. Even our method of timekeeping is directly related to the Earth’s relationship to the sun.

In my opinion, all this astronomic geekery is part and parcel with sci-fi. It informs the creation of your setting and dresses it. It’s taking our understanding of our universe and expanding on it in fantastic ways. So this planet we’re crafting will have a moderate elliptical orbit. Specifically an elliptical orbit that takes our planet from one edge of the circumstellar habitable zone to the other within a single complete rotation. I also don’t really want to futz with calendars all that much at this point so let’s say that our planet’s average distance from its parent star is somewhere near the same as Earth’s.

Unlike Earth, however, I want our planet to have a rotational axis perpendicular to the plane of its orbit. Which is to say that its the plane of its rotation is the same as its orbital rotation. This would mean that the planet would have no regional seasons since the same parts of the sphere would be closest to its star. The warmest parts of the planet would still be the region centered on the equatorial line and the coldest parts would be the poles.

BUT! We’ve established that our planet has an elliptical orbit, which would mean it would experience variations in climate as a whole world, instead of regionally. This wouldn’t change the extreme temperature zones, i.e. the equatorial zones would be warmest and the poles would be coldest but the average temperatures in these regions would go up or down based on the point of the planet’s orbit – and therefore its proximity to its star.

I think that’s enough for now. We’ve covered broad strokes of how the planet travels through the celestial realm and what affects that might have on its climate, which of course will inform how cultures develop on our world. For now, I’ll let the ideas of how I want to proceed percolate. But Starfinder is equal parts Science-Fantasy as it is Science-Fiction. There’s magic up in them there stars. So I think it’ll be important to tie in those elements as well. Next time, I’ll touch upon a few of those themes to flesh out what our world will become. For now I’ll just leave it with a name: Tsintuvael (sin-TOO-VAY-ell)…


What do you think of the return of Prep With Me articles? What else would you like to see from these? Let me know in the comments section below!

Anthony Li

Anthony Li has been pretending to be someone or something else for about as long as he can remember, which some people might consider a problem. He cut his teeth on 2nd Edition AD&D when he was 14 years old and his only regret is that he didn’t start rolling dice sooner. Due to an unhealthy addiction to Magic: the Gathering he missed the entire cultural phenomenon that was the 3.X era of D&D. After a brief stint with 4E, he was dragged kicking and screaming into the Pathfinder Roleplaying Game where he has since acclimated, adapted, and thrived. Most of his roleplaying experience has been behind in the GM screen where he has trained his dice to confirm crits on command. He always roots for the bad guys.