Astronomers have been astonished by the discovery of molecular oxygen in another galaxy for the first time outside the Milky Way.The discovery was made in the Markarian 231 galaxy, 561 million light-years from Earth. The findings are notable since the galaxy is powered by a quasar, a highly active supermassive black hole.The researchers used the IRAM 30-meter radio telescope in Spain to analyze the galaxy. However, the reason for the appearance of oxygen is still unclear. The possible reason could be the interaction between the active galactic nucleus-driven molecular outflow and the outer disc molecular clouds.