Top astronomers have been scouring the universe for signs of life and have detected unusually high levels of radiation in 50 different galaxies.
And the discovery has got many experts brimming with excitement about finding extraterrestrial life.
Of those, only 50 hinted at the presence of advanced life.
Radiation could be emitted by these alien civilisations in the same way Earth radiates heat and light.
Roger Griffith, a researcher from the Pennsylvania university and the lead author of the paper, said: "We found about 50 galaxies that have unusually high levels of mid-infrared radiation.