Genesis

Background

I was recently looking through an old issue of White Dwarf when I happened across a computer program, written in BASIC (pages 22-23), to generate a solar system for games such as Traveller. For some reason, I decided to try to rewrite it in Javascript. It wasn't entirely successful, partly because I had trouble reading some of the code in the online copy, but I did basically get it to work.

This led me to search out other similar implementations, such as the one by Ian Burrell which I also translated into a version that could run on a web page. I learned a lot from the experience of making these renderings and they inspired me to attempt my own version. It's a bit simpler than the other two because I like simple models and anyway have too limited a grasp on the maths of planetary physics to make it more accurate.

How it works

More details are available in the source code to this page but in outline, the model:

1. creates a star of one solar mass, equivalent to our own sun, surrounded by a void in space
2. seeds the void with a disk of dust, the equivalent mass of about fifty earths
3. one by one, creates a planetary nucleus to sweep up dust within its orbit and merge with any other proto planets that it comes across to become a terrestrial world such as Earth or Mars
4. if it grows large enough, it starts attracting gas as well to become a giant planet such as Jupiter or Neptune

Results

The resulting specifications for the planets are shown in comparison to Earth, so for example an orbit of 2.0 would be double the distance of Earth's orbit around the sun. Similarly, a mass of 0.5 would be half of the Earth's mass and a radius of 5.0 would be five times the Earth's radius.

Context

Finally, for the sake of comparison, I've presented our own solar system in the same terms below.