Researchers use the Dark Energy Spectroscopic Instrument to make the largest 3D map of our universe

With 5,000 tiny robots in a mountaintop telescope, researchers can look 11 billion years into the past. The light from far-flung objects in space is just now reaching the Dark Energy Spectroscopic Instrument (DESI), enabling ...

Understanding how our universe has evolved is tied to how it ends, and to one of the biggest mysteries in physics: dark energy , the unknown ingredient causing our universe to expand faster and faster. To study dark energy's effects over the past 11 billion years, DESI has created the largest 3D map of our cosmos ever constructed, with the most precise measurements to date. This is the first time scientists have measured the expansion history of the young universe with a precision better than 1%, giving us our best view yet of how the universe evolved.

Researchers shared the analysis of their first year of collected data in multiple papers that will be posted today on the arXiv pre-print server and in talks at the American Physical Society meeting in the United States and the Rencontres de Moriond in Italy. "We're incredibly proud of the data, which have produced world-leading cosmology results and are the first to come out of the new generation of dark energy experiments," said Michael Levi, DESI director and a scientist at the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab), which manages the project.

DESI has made the largest 3D map of our universe to date. Earth is at the center of this thin slice of the full map. In the magnified section, it is easy to see the underlying structure of matter in our universe. Credit: Claire Lamman/DESI collaboration; custom colormap package by cmastro Read more

This artist's rendering shows light from quasars passing through intergalactic clouds of hydrogen gas. Researchers can analyze the light to learn about distant cosmic structure. Credit: NOIRLab/NSF/AURA/P. Marenfeld and DESI collaboration Read more

As light from a distant quasar passes through gas in space, certain wavelengths of light are absorbed. Plotting the absorption lines reveals the "Lyman-alpha forest" (emphasized here in brown and green) and provides information about the distant clouds of gas between us and the quasar. Credit: David Kirkby/DESI collaboration Read more

DESI's Hubble diagram plots a characteristic pattern – baryon acoustic oscillations, or BAO "bubbles" – at different ages of the universe. The amount of dark energy determines how fast the universe grows, and therefore the size of the bubbles. The solid line is how big Lambda CDM predicts the bubbles will be, while the dashed line shows the prediction from a different model where dark energy evolves with time. DESI will gather more data to determine which model is a better description of the universe. Credit: Arnaud de Mattia/DESI collaboration Read more

A simplified explanation of the different parts of DESI's Hubble diagram. Credit: Claire Lamman/DESI collaboration Read more