A radio telescope in South Africa detected a cosmic megamaser from colliding galaxies 8 billion light-years away, revealing new insights into galaxy mergers.
Radio telescope detects distant cosmic signal
A radio telescope in South Africa called MeerKAT has detected an extremely bright radio signal coming from two galaxies that are colliding, located 8 billion light-years away. The discovery was made by a team from the University of Pretoria and described in a paper submitted to arXiv in February 2026, though it has not yet been peer-reviewed.Cosmic megamaser detected through gravitational lensing
Astronomers had previously not detected this type of emission beyond 3 billion light-years due to limitations in sensitivity. The signal was detected because a galaxy aligned with the line of sight acted as a gravitational lens, bending and amplifying the radiation much like a magnifying glass.Maser explained
A maser is similar to a laser but emits energy in radio waves instead of visible light. In dense molecular clouds, hydroxyl molecules—composed of one oxygen atom and one hydrogen atom—absorb infrared radiation from nearby stars and then emit it together on a very narrow radio frequency band.Power of a megamaser
The resulting beam from this process can be millions of times more powerful than an ordinary maser found in our galaxy. Astronomers call this intense emission a megamaser, which is often associated with galaxy collisions.Galaxy collisions and star formation
These powerful radio beacons are linked to galaxy collisions, where compressed gas from the encounter triggers a burst of star formation and heats surrounding dust. The source detected by MeerKAT, HATLAS J142935.3-002836, corresponds to two galaxies merging, a process that will eventually happen when the Milky Way and Andromeda galaxies collide in about 5 billion years.
