Cosmic laser beam detected: ancient signal from 8 billion light-years away

Astronomers have detected a breathtaking phenomenon emanating from the distant universe: a colossal cosmic laser beam aimed directly at Earth. This unprecedented discovery, the brightest and most remote megamaser ever observed, offers a tantalizing glimpse into the universe's violent past.

Ancient cosmic flashlight illuminates deep space

The signal, a powerful microwave emission from a hydroxyl megamaser, originates from the colliding galaxy system HATLAS J142935.3–002836, a system first identified in 2014. The detection, made using the MeerKAT radio telescope in South Africa, is possible due to a rare alignment of spacetime predicted by Albert Einstein over a century ago – a phenomenon known as gravitational lensing.

Megamasers, akin to human-made lasers but amplifying microwaves instead of visible light, are born from the intense collisions of galaxies. When galaxies merge, vast clouds of gas are compressed, triggering the release of hydroxyl molecules, which emit high-intensity microwave radiation. The observed signal boasts a wavelength of approximately 18 centimeters, significantly stronger than other known megamasers.

The extraordinary brightness of this particular megamaser suggests it might be a gigamaser, a theoretical and even more extreme category of these cosmic beacons. The signal’s age is remarkable; it dates back to a time when the universe was roughly half its current age. Gravitational lensing played a key role in making this detection possible. The immense gravity of an intervening massive object warped spacetime, bending and amplifying the light from the distant source.

“This system is truly extraordinary,” explains the lead author of the study.