Nasa’s Kepler telescope has discovered more than 100 Earth-sized planets orbiting alien stars.

Nine small planets have also been discovered within the so-called habitable zone, where conditions are favourable for liquid water – and potentially life, BBC reports.

The finds are contained within a catalogue of 1,284 new planets detected by Kepler – which more than doubles the previous tally.

Nasa said it was the biggest single announcement of new exoplanets.

“This gives us hope that somewhere out there, around a star much like ours, we can eventually discover another Earth,” said Ellen Stofan, NASA chief scientist in a statement.

The researchers used a statistical analysis method which can be used on many candidate planets at the same time – speeding up the verification process.