CACTUS (Converted Atmospheric Cherenkov Telescope Using Solar-2) was a ground-based,
Air Cherenkov Telescope (ACT) located outside
Daggett, California, near
Barstow. It was originally a solar power plant called
Solar Two, but was converted to an observatory starting in 2001. The first astronomical observations started in the fall of 2004. However, the facility had its last observing runs in November 2005 as funds for observational operations from the
National Science Foundation were no longer available.[1] The facility was operated by the
University of California, Davis but owned by
Southern California Edison.[2]
It was demolished in 2009.[3]