NASA has added hundreds of new confirmed exoplanets to its list of known worlds in deep space, significantly boosting the number of faraway planets we know about.

NASA scientists and several university researchers had put ExoMiner to work on data from an archive of possible but unconfirmed exoplanets.

Hamed Valizadegan, ExoMiner project lead and machine learning manager with the Universities Space Research Association at NASA's Ames Research Center in California, said in a press release: "When ExoMiner says something is a planet, you can be sure it's a planet.

Direct imaging is difficult and only just over one percent of exoplanets have been confirmed this way.

Indeed, the vast majority of exoplanets we know about are either gas giants or gassy planets around the size of Neptune.