Einstein's Theory Unlocks Universe's Most Powerful Space Laser, Billions-Year-Old Signal

• Scientists discovered the most distant and brightest 'space laser' (megamaser) ever, formed by two colliding galaxies.
• The megamaser, named HATLAS J142935.3-002836, is a 'hydroxyl megamaser' emitting microwaves/radio waves, not visible light.
• Einstein's theory of 'gravitational lensing' allowed detection; a massive object bent spacetime, magnifying the distant signal.
• Megamasers are rare, found in gas-rich galaxies, and indicate accelerated star formation during galaxy mergers.
• The presence of a megamaser may suggest two active black holes, potentially generating gravitational waves in the future.