A CUTTING-edge new telescope instrument designed and built by an international team including Durham University has been officially launched.

The Dark Energy Spectroscopic Instrument (DESI) aims to create the most extensive 3D map of the universe to date and reveal the nature of the mysterious dark energy that scientists believe is driving its expansion.

DESI will capture and study the light from about 30 million galaxies and other distant objects in the universe.

Scientists say this will help them construct a 3D map of the universe with unprecedented detail.

They also hope that the data will help them better understand the repulsive force associated with “dark energy” that is causing the expansion of the universe to accelerate across vast cosmic distances.

DESI is an instrument installed on the Nicholas U Mayall 4-metre Telescope at the Kitt Peak National Observatory in Arizona, USA, and brings together 500 scientists at 75 institutions across 13 countries.

The instrument features new optics that increase the field of view of the telescope and includes 5,000 robotically controlled optical fibres to gather spectroscopic data simultaneously from an equal number of objects.

The fibre-optic system, led by Durham, will split light from objects in space such as galaxies, quasars and stars into narrow bands of colour and will reveal their relative distance and velocity as well as information about their chemical composition.

By looking at how far and how quickly galaxies and quasars are moving away from our planet, researchers will be able to gauge how much and how fast the universe has been expanding.

As the universe expands, galaxies move away from each other, and light from them shifts to longer, redder wavelengths.

By measuring these galaxy redshifts, DESI researchers will create a 3D map of the universe. The detailed distribution of galaxies in the map is expected to yield new insights on the influence and nature of dark energy and perhaps also dark matter.

Professor Carlos Frenk, Ogden Professor of Fundamental Physics at Durham University’s Institute for Computational Cosmology, said: “We have been preparing for this moment for the past five years. DESI will collect about ten times more data than all previous surveys put together.

“We are searching for clues about the nature of dark energy but, in the process, we will also learn about dark matter and about how galaxies form and evolve.

“But perhaps, as we have seen from previous ground-breaking surveys, we will discover something entirely new about our universe.”

The formal start of DESI’s five-year survey follows a four-month trial run of its custom instrumentation that captured four million spectra of galaxies – more than the combined output of all previous spectroscopic surveys.

Project Director Michael Levi, at Berkeley Lab, USA, said: “We will measure ten times more galaxy spectra than ever obtained. These spectra get us a third dimension.”

Instead of two-dimensional images of galaxies, quasars, and other distant objects, he explained, the instrument collects light, or spectra, from the cosmos such that it “becomes a time machine where we place those objects on a timeline that reaches as far back as 11 billion years ago”.

DESI is supported by the DOE Office of Science and by the National Energy Research Scientific Computing Center, a DOE Office of Science user facility, USA, the US National Science Foundation, the Gordon and Betty Moore Foundation, the Heising-Simons Foundation, the French Alternative Energies and Atomic Energy Commission (CEA), the National Council of Science and Technology of Mexico, the Ministry of Economy of Spain, and by the DESI member institutions.

DESI is supported in the UK by the Science and Technology Facilities Council.

The Nicholas U. Mayall 4-metre Telescope is located at Kitt Peak National Observatory, a programme of the National Science Foundation’s (NSF) NOIRLab, USA.