Boffins are putting together a new catalogue of all the confirmed planets that could harbour extraterrestrial life, with seven worlds in our Milky Way making the list so far.

The Habitable Exoplanets Catalog, a project of the Planetary Habitability Lab at the University of Puerto Rico, looks at the planets spotted by the High Accuracy Radial Velocity Planet Searcher (HARPS) and the Kepler Space Telescope and narrows those worlds down to those with the most potential for life.

There are nearly 80 confirmed exoplanets in the sky and 250 Kepler candidates, all similarly sized to Earth, but only a few of them could really support life because they're the right distance from their sun to have liquid water.