Quiz time: This week we’re spotlighting news about the Dark Energy Spectroscopic Instrument.
But first, join Fermilab News at Work in congratulating Sandra Efstathiou for winning last week’s quiz. CMB-S4 sensors will achieve unprecedented sensitivity, detecting nanokelvin fluctuations in the cosmic microwave background. Thank you to everyone who participated.
Now, show off your knowledge of the news coming out of Fermilab in this week’s quiz. A winner will be randomly selected from all lab employees and users who submit the correct answer to today’s question by noon CT today, Nov. 1.
This week’s question: What do spectrographs on the Dark Energy Spectroscopic Instrument measure? (Hint: See “DESI opens its 5,000 eyes to capture the colors of the cosmos.”)
Good luck! We will announce the winner and answer next week.
Past winners are welcome to participate in the quiz each week. However, only one win per person will be recognized in any 30-day period. The winner is recognized in the following week’s quiz and rewarded with a small token.

DESI’s 5000 spectroscopic “eyes” can cover an area of sky about 38 times larger than that of the full moon, as seen in this overlay of DESI’s focal plane on the night sky (top). Each one of these robotically controlled eyes can fix a fiber-optic cable on a single object to gather its light. Photo: DESI collaboration