[Constellation. Photo Credit to Pixabay]

On April 15th, scientists working with the Dark Energy Spectroscopic Instrument (DESI) unveiled the largest high resolution 3D map of the universe ever created, marking the end of their five year mission and another milestone in humanity’s quest to understand the cosmos.

This massive 3D map charted positions of 47 million galaxies and quasars, as well as 20 million stars and other faint objects, spanning across 11 billion years of cosmic history. 

Scientists state this newly collected data will assist in the study of dark energy- an unknown, mysterious force constituting approximately 68.3 to 70% of the universe and propelling its accelerated expansion.

DESI’s effort to better understand dark energy first gained major attention in 2025 when their first group of analysis indicated that dark energy evolves over time.

This fundamentally challenged long-standing astronomical beliefs that dark energy was and would stay constant.

At that time, there was no finalized proof that this was true.

However, this novel 3D map may be the key to a full verdict.

By mapping how galaxies and stars have been distributed across time and space over billions of years, scientists are now able to track the path of expansion across the universe.

“Now that we have that final data set, the cosmologists will be working hard to unpack any subtle new features of dark energy revealed by the data,” Adam Myers, co-manager for DESI’s survey operations, told Gizmodo. “Complementary datasets have also grown larger, and analysis techniques are constantly being refined, so watch this space!”

DESI began collecting data in May 2021.

The original five-year plan was to capture light from 34 million galaxies and quasars.

For this project, DESI used  the 4-metre-class Nicholas U. Mayall Telescope stationed at Kitt Peak National Observatory in Arizona.

5000 robotic fiber-optic positioners were mounted on the telescope.

These small robotic arms would move every 20 minutes, capturing faint lights across the night sky.

After the data was collected, it was sent to a spectrograph and split into color components.

Scientists would then use variations in color to calculate how far each galaxy was from earth, and in the end create the 3D map layer by layer.

The project faced various challenges such as the COVID-19 pandemic and the 2022 Contreras Fire, which swept across Kitt Peak.

Despite these setbacks, the project persisted, ultimately surpassing all expectations.

The data equated to about 80 gigabytes per night.

It ended up exceeding the original plan by observing 47 million galaxies and 20 million stars.

The 3D map encompasses 6 times as many galaxies and quasars as all previous measurements combined, and covered two-thirds of the northern sky.

As a result, DESI has even added a new side project called the “Bright Time Survey” – gathering data to study how reflected light from the moon would affect observation of faint and distant objects. 

With this vast amount of data, a significant breakthrough regarding dark energy is highly probable.

In the meantime, DESI will continue to survey new parts of the night sky until 2028. 

Plans include expanding the map by about 20 percent, cover areas closer to the plane of the Milky Way, and even extend into the southern skies.

Additionally, researchers will also study red galaxies, dwarf galaxies, or stellar streams across the Milky Way.

Nonetheless, their overall goal remains the same – finding the true nature of dark energy.

Miceal Levi, project director of the DESI, said, “We’ve built a remarkable piece of equipment that met all our expectations and then some.” 

“Now we’re pushing beyond our original plan. We don’t know what we’ll find, but we think it’ll be pretty exciting.”