Astronomers detect laser pulse from an object 8 billion light-years away
An international team has detected an exceptionally powerful microwave signal from deep space. The group, affiliated with the University of Pretoria in South Africa, used the MeerKAT radio telescope to record what they describe as one of the most energetic phenomena of its kind.
Where the signal came from
The microwave radiation comes from a merging galaxy system labelled HATLAS J142935.3.002836, about 8 billion light‑years away. The signal appears during a galaxy collision, when massive forces compress gas clouds and trigger bursts of star formation, similar to events during cosmic reionization. Those collisions can spawn millions of new stars.
The emission is a hydroxyl megamaser (a natural “radio laser” that amplifies microwaves). As the clouds are compressed during the merger, the molecules become excited and produce this powerful output. The strength is so notable that researchers suggest it may fall into an extreme category called “gigamasers”: emissions billions of times brighter than ordinary maser beams. The galaxy system was called “really extraordinary” by Thato Manamela, a postdoctoral researcher at the University of Pretoria.
How gravitational lensing and MeerKAT helped
This detection was aided by gravitational lensing, an effect described by Albert Einstein. A foreground galaxy’s gravity bends and stretches spacetime, magnifying the signal from the distant system. That boost meant a stronger signal reached Earth’s radio telescopes, with the MeerKAT radio telescope playing a central role in recording it.
The team shared their results on arXiv (the online preprint archive), providing the scientific community with access to the detailed data. By combining gravitational lensing with radio searches, researchers hope to find 100 to 1,000+ more megamasers, which would allow a richer study of galaxy evolution and collisions over billions of years.
How galaxy collisions reshape galaxies
Galaxy mergers do more than trigger star formation. These large-scale events also alter galaxies’ shapes, often turning spirals into rounder elliptical systems. The turbulence and compression push gas into dense knots where stars form, reshaping the galaxies involved. Geo.de has described how these processes change a galaxy’s structure and appearance.
Closer to home, the Milky Way is on a collision course with the Andromeda galaxy, expected in about 5 billion years. While individual stars and planetary systems mostly pass one another without direct hits, the overall systems will be rearranged. By then, our Sun will have swollen into a red giant, leaving Earth uninhabitable.
Studying signals like this one helps astronomers reconstruct how galaxies interact and change over time. With further observations, researchers expect to learn more about the processes that have shaped the universe we see today.