Upcoming Super Telescope Will Study the Universe’s Most Extreme Explosions

The European Commission recently established a planned gamma-ray observatory as a European Research Infrastructure Consortium, or ERIC, which will expedite the construction of the telescope and set up a framework for the distribution of its data.

In other words, we’ll soon have a record-breaking observatory for studying gamma ray sources—some of the most energetic and mysterious objects in the universe. The observatory’s full name is the Cherenkov Telescope Array Observatory (CTAO), and it will be the “world’s most powerful ground-based observatory for very high-energy gamma-ray astronomy,” according to the European Southern Observatory. On February 13, the ERIC Council gave the go-ahead for Japan to be a strategic partner and recognized the United States, Brazil, and Australia as third-party members, setting the stage for the telescope’s path to reality.

Gamma rays are the most energizing waves in the electromagnetic spectrum. They are produced by some of the most energetic objects in the universe—including black holes, neutron stars, and supernovae—but also by regular ol’ thunderstorms here on Earth.

“Over the last decade, people have discovered that these high-energy gamma rays are present in many, many types of very energetic astronomical phenomenon, but we don’t know much about where they come from,” said Dave Kieda, an astronomer at the University of Utah and CTAO spokesperson for the U.S., in a university release.

The brightest gamma-ray burst of all time, or the BOAT, was spotted in October 2022. The 1-in-10,000-year event showcased the extremity of gamma rays in our universe, and raised more questions about the intense objects that spew gamma rays into the cosmos.

CTAO will consist of two telescope arrays, one of which will be on the Spanish island La Palma and the other at ESO’s Paranal Observatory. But ESO officials are currently worried that the clear skies above Paranal—some of the clearest on Earth—are under threat from a proposed industrial project near the site, which could reduce the remarkably dark environment that helps the observatory see deep into space.

The Earth’s atmosphere stops gamma rays from reaching the planet’s surface, but the rays interacting with the atmosphere produces high-energy particles.

“These particles travel faster than the speed of light in air and as a result they emit a flash of eerie blue Cherenkov radiation — similar to a sonic boom created by an aircraft exceeding the speed of sound,” according to an ESO release. “The CTAO’s mirrors and high-speed cameras will capture these short-lived flashes and pinpoint their direction. This will allow each gamma ray to be traced back to its cosmic source, allowing astronomers to address some of the most enduring mysteries in astrophysics.”

The CTAO will include 64 telescopes around the world—13 in the Northern Hemisphere and 51 in the Southern Hemisphere. The data from the observatory will be made open-access, as will its analysis software, which will help the astronomical community mine the telescopes’ observations for new discoveries about the cosmos.

The CTAO’s first telescopes are expected to be delivered by early 2026, so there won’t be any gamma-ray observations this year. But the latest moves set the stage for the observatory’s construction, which could open new doors in high-energy astrophysics.