Alien worlds have been discovered beyond our own galaxy for the first time, according to astronomers.
Scientists now regularly find exoplanets within the Milky Way and 403 have been catalogued since 1995. The furthest resides around 20,000 light years away.
But Erin Mentuch from the University of Toronto, Canada, made her find far deeper into space.
Ms Mentuch analysed 88 remote galaxies using data from the Gemini Deep Deep Survey. The light was emitted from them when the Universe was between a third and a half its current age – some seven to 10 billion years ago.
The galaxies were far too remote to view stars individually but their light output was found to peak at two distinct wavelengths. The short wavelength was the combined light of a galaxy’s stars while the longer came from the glowing interstellar dust.
However, the PHD student noticed there was a faint third component between the peaks. This mysterious light was too cold to be produced by stars but too warm to be dust.
Ms Mentuch concluded it was most likely caused by circumstellar discs – swirling clouds of dust and gas forming young solar systems around infant stars.
‘It’s the most surprising result I’ve ever worked on,’ said Ms Mentuch’s PHD supervisor Roberto Abraham, who collaborated on the project.
The discovery may show show how the rate of planet formation has changed over billions of years.