The largest map of the universe ever created

Added: 2026-05-06

[00:00:00]The slide show I'm going on behind me shows how astronomers have over the past 5 years built up the largest 3D map of the universe ever assembled. Every dot on that map is a galaxy containing millions of stars and millions of planets. This is the handywork of the Dark Energy Spectroscopic Instrument or DESI, which is fitted to a mountain top telescope in Arizona. It has 5,000 little tiny robot arms and each one positions of 5,000 optical fibers in the focal plane of the telescope so that each fiber captures the light of a single galaxy. The aim is to understand why the expansion of the universe is speeding up. The universe has been growing ever since the Big Bang, but lately it appears to be expanding faster. By looking at how the galaxies have clustered through time, through the history of the universe, they can see whether that mysterious acceleration, which they call dark energy, has been steady or whether it's getting faster or getting slower. And that'll help them understand where the universe may be going and what its ultimate fate may be.