Really interesting. They're using a Hough transform, which is used to pick out shapes from an image (lines and circles most often), especially popular before ML techniques for object recognition existed.

Sounds like a great way to search for asteroids, never would have thought of it.

It's essentially just a coordinate transform that lets you add up evidence for a particular object, and the objects stand out as little bright points.

I'm sure they're doing lots of clever things on top of it of course though.