Astronomers have identified several strange, ring-like objects in deep space that defy current classifications. These formations, dubbed Odd Radio Circles (ORCs), glow more brightly along their edges when observed through radio telescopes but remain largely invisible in optical and infrared light. Their origins are unknown, and they appear unlike anything previously documented in astronomy.
Unexplained Cosmic Rings in Deep Space
ORCs vary in size, with some spanning hundreds of thousands of light-years—larger than the Milky Way. Their exact locations remain uncertain, but they are positioned far from the plane of our galaxy, suggesting they may be linked to distant galaxies. In several cases, visible galaxies appear at the center of these circles, hinting that their formation might be related to galactic activity.
What Could Be Causing ORCs?
Since their discovery, scientists have been working to understand what these unusual objects might be. Several theories have been proposed, but none provide a complete explanation for all known ORCs. Astronomers have ruled out common celestial phenomena such as supernovae, planetary nebulas, star-forming regions, and gravitational lensing.
One possibility is that ORCs are remnants of massive shockwaves from ancient galactic explosions. Others speculate they could be linked to merging supermassive black holes, which may generate vast spherical shockwaves detectable in radio frequencies. Another idea suggests ORCs might be the result of galactic winds—powerful streams of charged particles ejected by galaxies with active star formation or supermassive black hole activity.
Recent studies suggest some ORCs may also emit faint X-ray radiation, which could indicate high-energy processes occurring in or around them. This challenges the earlier assumption that they were purely radio-based phenomena.
Astronomer Kristine Spekkens of the Royal Military College of Canada and Queen’s University believes ORCs could represent a new class of astronomical objects. “These could be something entirely new, or they might be an extension of a phenomenon we’ve never been able to observe before,” she explained.
A Closer Look at The Deep Space ORCs
Despite emitting strong radio signals, ORCs are difficult to detect in other wavelengths of light, making them particularly mysterious. Interestingly, some appear very close to each other, suggesting they may have a shared origin.
Recent follow-up studies using South Africa’s MeerKAT radio telescope have revealed intricate internal structures within some ORCs, including multiple arcs. This suggests they are more complex than simple radio halos, potentially pointing to a dynamic formation process involving shockwaves or turbulence in space.
Read More: Giant Structure Discovered in Deep Space May Change Our Entire Perspective on the Universe
First Sightings and Future Discoveries
Three ORCs were initially detected in 2019 during a deep-space survey using Australia’s Square Kilometre Array Pathfinder (ASKAP) telescope. This discovery was part of the Evolutionary Map of the Universe (EMU) project, designed to map millions of previously unknown radio sources. Additional ORCs were later identified in archival data from India’s Giant Metrewave Radio Telescope (GMRT) and through further observations with MeerKAT.
MeerKAT has provided some of the clearest images yet, revealing that at least one ORC consists of multiple concentric rings, suggesting it formed through a series of cosmic events rather than a single explosion. In 2024, an ORC measuring 370,000 light-years across—twice the size of the Milky Way—was discovered, highlighting that these objects can be far larger than initially thought.
The Search for More ORCs in Deep Space
So far, at least six ORCs have been detected, but astronomers believe many more are waiting to be discovered. The EMU project is still in its early stages and is expected to significantly expand the catalog of known radio sources—from 2.5 million to an estimated 70 million. This means future surveys could uncover additional ORCs, providing more clues about their origins and significance.
“This is just the beginning,” said Spekkens in an interview with Live Science. “Every time we develop a new way to observe the universe, we find things we never imagined.” A research paper detailing these discoveries has been submitted to Nature Astronomy for peer review and is also available as a preprint on arXiv.
Read More: NASA Will Pay SpaceX Up to $843 Million to Destroy the International Space Station