Despite the fact that planets seem very common in the universe they are tiny, faint objects at cosmic scales; this makes their detection difficult with current technology. For this reason, most exoplanets have been detected with indirect methods. Of these, the most successful has been the radial velocity method. HARPS (the High Accuracy Radial-velocity Planet Searcher) has allowed the discovery of a number of planets with masses below that of Neptune orbiting nearby stars. However, few of these planets are among the smallest ever discovered, or reside in its star's habitable zone. The possibility exists that one of these planets is covered by oceans; this discovery is an encouraging result in the search for planets which could support life.