The team concluded that about one of every three known planetary systems could harbour Earth-like planets in habitablezones further out than the Hot Jupiters.
This raises the possibility that planets like ours orbiting in habitablezones could be covered in oceans - providing all the key constituents required for life.
According to Dr Lissauer, about 50 of the 1, 200 or so candidate planets (if planets they be) are orbiting in the habitablezones of their parental stars.