Before DESI, the Dark Energy Spectroscopic Instrument, can begin its 5-year mission from an Arizona mountaintop to produce the largest 3-D sky map yet, researchers first needed an even bigger 2-D map of the universe.
![](https://scx1.b-cdn.net/csz/news/tmb/2021/buildingagia.jpg)
Source:
https://phys.org/news/2021-01-giant-d-universe-largest.html