Sanatorium Times

Visualizing known exoplanet locations

The visualization (web page loads approx. 10MB of data - this may take a while)

There are currently over a thousand known exoplanets and thousands of likely candidates on top of that. The databases contain all kinds of information on the planets.

I often wondered where all these exoplanets are. Of course, you could point at a dot in the night sky and say "there", but that doesn't tell us how far it is and what other stars and exoplanets are near it. For that, you would need a map. It seems that no one ever created one. Sure, there is a lot of planetarium software out there (like Stellarium). Most of them seem to focus on rendering the sky as seen from earth. That's not particularly helpful when you want to see earth's neighbours in three dimensions. Folks at Google created 100.000 Stars, a web technology demonstration which shows the real position of about 100k stars taken from star catalogs. It's a beautiful presentation.

Yet, it does not cover exoplanets. So I went and hunted down catalogs of stars and exoplanets that not only listed azimuth and elevation (the point in the sky where you see the star), but also distance. With a tiny bit of massaging, I converted that to a list of points that could be rendered in three dimensions. Unfortunately, only a third of the listed exoplanets has distance information included. These roughly 650 planets are the only ones I could include in the map. Too bad, but that cannot be helped.

Creating a small desktop program to navigate the resulting map would be a simple job. This is why I decided to try out WebGL and Javascript myself as I have been a tiny bit curious about WebGL for a long while. Interestingly, actually rendering the point cloud was the simplest task for me. Loading the data and getting the input for some camera navigation turned out to be the harder part. The result is functional, but not very beautiful (as always) and quite rudimentary. But it gives a rough idea of where everything is located. And it also shows how skewed that data set is because the Kepler space observatory only looked at a single section of the sky in its hunt for exoplanets.