Sloan Foundation 2.5m Telescope

Sloan Foundation 2.5m Telescope

Changing a cartridge, opening the enclosure, sunset, and nightly observing at the Sloan Foundation 2.5m Telescope at Apache Point Observatory, Sunspot, New Mexico. During the night, an observer changes the cartridge to observe a new set of stars or galaxies roughly every hour. Each cartridge contains hundreds of fiber-optic cables plugged into holes in a large aluminum plate. Each fiber observes a single star or galaxy. The "bright time" observing is during a nearly full moon, the "dark time" is before moonrise, with the moon (not the sun!) rising shortly before the end of the video. The orange glow in the background is from the city of El Paso, Texas, 90 miles to the south. The multi-colored lights briefly shining through the telescope petals before and after cartridge changes are calibration sequences. We use different light sources to check that all parts of the instrument see light the same way and to compare the observations to known standards.  

Music from "Just Ancient Loops" Composed by Michael Harrison, Cellos performed by Maya Beiser From the Cantaloupe Music CD Time Loops. Video: Sloan Digital Sky Survey