sunlight.live



I recently wanted to make a pixel worldmap, and dusted my undergrad astronomy books to create this illustration. It shows the Sun's terminator, the line which divides "day" and "night" on earth.

Detailed information and the creation steps can be read on my blog, while the source is available on this GitHub repo. Feel free to raise an issue to suggest improvements or offer insights, especially if you can share any astronomy knowledge!


This whole website is updated every 10 minutes using cron+Python3, a single line of NumPy plus some celestial mechanics formulas, and should have an accuracy of ±1 degree. The goal was to create a minimal, fast and aesthetically pleasing result. I'm not much of a designer, but I'm pretty pleased with the first version of this site.

The plotting happens using Matplotlib. Most Matplotlib code and tutorials are unfortunately very confusing, but I think the source can serve as a guide to readable and maintainable plotting.

The world data is obtained from the wonderful Natural Earth datasets, and handled using GeoPandas.


Roadmap? Once I have some time, I want to :

• Learn more about the accuracy of astronomical formulas
• Offer some more astronomical data through this page and an API
• Provide some more illustrations about our beautiful planet and its moon

Paschalis, out!