The DESI (Dark Energy Spectroscopic Instrument), currently pointed skyward from its home in the Nicholas U. Mayall Telescope at Kitt Peak National Observatory in Arizona, is tasked with tracking the expansion of space, to study dark energy & create the most detailed 3D map. of the Universe that was never put together.
It’s only been 7 months since the DESI mission began, and we already have a record-breaking, stunning 3 dimensional image of the galaxy all around us, demonstrating DESI’s capabilities & potential it has for mapping space.
DESI has already cataloged & charted over 7.5 million galaxies, with over a million new additions per month. By the scan is fully complete in 2026, It is thought that more than 35 million galaxies will have been mapped, providing astronomers with a huge data library to mine.
“There’s a lot of beauty there,” says astrophysicist Julien Guy from Lawrence Berkeley National Laboratory in California.
“In the distribution of galaxies in 3D map, there are huge clusters, filaments & voids. These are the big structures in the Universe. But within them you will find an imprint of the early Universe & history of its expansion since then.
DESI is made up of 5,000 optical fibers, each individually controlled & positioned by its own little robot. These fibers must be precisely positioned within 10 microns or less-than the thickness of a human hair, and then capture glimpses of light as they filter down to Earth from cosmos.
Using this fiber network, the instrument acquires images of the color spectrum of millions of galaxies, covering more than a third of the entire sky, before calculating how much light has been redshifted, that’s that is, how far it has been pushed towards the red end of spectrum due to expansion of the Universe.
As this light can take many billions of years to reach Earth, it is possible to use the redshift data to see the depth of the Universe – the greater the redshift, the more something is far away. Additionally, facilities mapped by DESI can be reverse engineered to see the initial formation in which they began.
DESI’s main goal is to reveal more about dark energy that thought to make up 70% of the Universe and to accelerate its expansion. This dark energy could drive galaxies in-to infinite expansion, cause them to collapse-back on themselves or something in between – and cosmologists are eager to narrow down the options.
“DESI will help us look for clues about the nature of dark energy,” Carlos Frenk, a cosmologist at Durham University in the UK, told the BBC.
“We will also learn more about dark matter & the role it plays in how the formation of galaxies like the Milky Way & how the evolution of the universe.
The previously released 3D map shows that scientists don’t have to wait for DESI to finish its work to benefit from its deep view of space. Other enhanced DESI research is investigating whether or not smaller galaxies, have their own black holes like large galaxies do.
The best way to spot a black hole is to identify the gas, dust & other materials dragged into it, but that’s not easy to spot in smaller galaxies, Something that collapses from DESI’s high Prison Spectra’s data should help with.
Then there is the study of quasars, particularly bright galaxies powered by supermassive black holes that act as sign post throughout billions of years of space history. DESI is used to test a hypothesis around quasars: which begin surrounded by a dust shell that driven-off over time.
The amount of dust around a quasar is believed to affect the color of the light it emits, that maks it a perfect task for DESI. The instrument should be able to gather information on about 2.4 million quasars by the time it completes its survey.
“DESI is really cool because it detects much fainter and much redder objects,” says Durham University astronomer Victoria Fawcett.
“We find many exotic systems, including large samples of rare objects that we simply have not been able to study in detail before.
You can keep up to date with the latest news from Dark Energy Spectroscopic Instruments on the official homepage.