The Catalina Sky Survey (CSS) is a Survey of Near-Earth Objects, i.e., Comets and Asteroids whose orbits pass close to that of the Earth. It was begun in 1998 and progresses.
The first goal has been to identify 90% of objects 1 kilometer or larger.
Two telescopes are used: 1.5meter telescope on Mt. Lemon and a 68 cm telescope near Mt. Bigelow, both near Tucson, Arizona.
Data from the same telescopes is used for the Catalina Real-Time Transient Survey, scanning the images for Transients.