European Commission Establishes Groundbreaking Gamma-Ray Observatory

The European Commission has recently designated a planned gamma-ray observatory as a European Research Infrastructure Consortium (ERIC), paving the way for the construction of the telescope and establishing a framework for the distribution of its data.

In essence, this development will soon lead to the creation of a record-breaking observatory for studying gamma-ray sources, which are among the most energetic and mysterious objects in the universe. The observatory, known as the Cherenkov Telescope Array Observatory (CTAO), will be the “world’s most powerful ground-based observatory for very high-energy gamma-ray astronomy,” according to the European Southern Observatory. The ERIC Council has given the go-ahead for Japan to become a strategic partner and has recognized the United States, Brazil, and Australia as third-party members, marking a significant milestone in the telescope’s path to reality.

Gamma rays are the most energetic waves in the electromagnetic spectrum, produced by highly energetic objects such as black holes, neutron stars, and supernovae, as well as by ordinary thunderstorms on Earth. Dave Kieda, an astronomer at the University of Utah and CTAO spokesperson for the U.S., noted, “Over the last decade, people have discovered that these high-energy gamma rays are present in many types of very energetic astronomical phenomena, but we don’t know much about their origins.”

The brightest gamma-ray burst of all time, known as the BOAT, was detected in October 2022, showcasing the extremity of gamma rays in our universe and raising further questions about the intense objects that emit gamma rays into the cosmos. The CTAO will comprise two telescope arrays, one located on the Spanish island of La Palma and the other at ESO’s Paranal Observatory. However, ESO officials are concerned that the clear skies above Paranal, which are among the clearest on Earth, are under threat from a proposed industrial project near the site, potentially reducing the dark environment that enables the observatory to see deep into space.

The Earth’s atmosphere prevents gamma rays from reaching the planet’s surface, but the interaction between gamma rays and the atmosphere produces high-energy particles. These particles travel faster than the speed of light in air, emitting a flash of eerie blue Cherenkov radiation, similar to a sonic boom created by an aircraft exceeding the speed of sound. The CTAO’s mirrors and high-speed cameras will capture these short-lived flashes, allowing astronomers to pinpoint their direction and trace each gamma ray back to its cosmic source, addressing some of the most enduring mysteries in astrophysics.

The CTAO will feature 64 telescopes worldwide, with 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, enabling the astronomical community to mine the telescopes’ observations for new discoveries about the cosmos. The first telescopes are expected to be delivered by early 2026, setting the stage for the observatory’s construction, which could open new doors in high-energy astrophysics.