The Sloan Digital Sky Survey or SDSS is a major multi-spectral imaging and spectroscopic redshift survey using a dedicated 2.5-m wide-angle optical telescope at Apache Point Observatory in New Mexico, United States. The project began in 2000 and was named after the Alfred P. Sloan Foundation, which contributed significant funding.
SDSS imaging camera
SDSS spectroscope cartridge
Aluminum plate close-up showing optical fibers
Quasars acting as gravitational lenses. To find these cases of galaxy–quasar combinations acting as lenses, astronomers selected 23,000 quasar spectra from the SDSS.
The Apache Point Observatory is an astronomical observatory located in the Sacramento Mountains in Sunspot, New Mexico, United States, approximately 18 miles (29 km) south of Cloudcroft. The observatory is operated by New Mexico State University (NMSU) and owned by the Astrophysical Research Consortium (ARC). Access to the telescopes and buildings is private and restricted.
ARCSAT and SDSS telescope buildings at the Apache Point Observatory.
The ARC 3.5-meter telescope
Enclosure of the SDSS