Kitt Peak National Observatory

DESI will capture and study the light from tens of millions of galaxies and other distant objects to better understand our universe and the properties of dark energy. The formal start of DESI’s five-year survey follows a four-month trial run of its custom instrumentation that captured 4-million spectra of galaxies — more than the combined output of all previous spectroscopic surveys. Fermilab has contributed multiple components to the international collaboration led by Berkeley Lab.

Installation has begun for the Dark Energy Spectroscopic Instrument, a next-generation astrophysics tool. Fermilab is managing key parts of the construction of the instrument, which will begin its five-year observation run in 2019.

Powerful survey instruments help us map the sky with incredible precision. But what ensures that the instruments themselves are precisely built?