Astronomers believe mysterious signals - previously dismissed as stellar bursts - are coming from an Earth-like planet.
The Gliese 581d planet has conditions that could support life, and is likely to be a rocky world, twice the size of Earth.
Signals from the planet were initially discovered in 2010, but last year dismissed as noise from distant stars.
Now, a further study claims that the 2014 research was based on 'inadequate analyses of the data' and that Gliese 581d does exist.