Removing the old camera for the Mayall 4-meter telescope.

The original 45-year-old top end of the Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory, a Program of NSF NOIRLab, being removed and a new top ring being placed in the dome. The ring supports the optics for the Dark Energy Spectroscopic Instrument (DESI), a state-of-the-art spectrometer that can measure the spectra of 5000 astronomical objects simultaneously. DESI is exploring the mysterious physics of dark energy.