The closest known extrasolar planet may also be one of the most Earth-like worlds ever discovered. Situated only 4.2 light years away in orbit around the red dwarf star Proxima Centauri, the terrestrial planet Proxima b, which was first discovered back in August 2016, could be a genuine Earth 2.0. Previous studies had suggested that this neighboring world was around 1.3 times the mass of the Earth, but now new observations have revealed that it is actually much closer than that. Key to this revelation was the Echelle Spectrograph for Rocky Exoplanet and Stable Spectroscopic Observations (ESPRESSO) instrument that is currently mounted on the European Southern Observatory's (ESO) Very Large Telescope in Chile. "We were already very happy with the performance of HARPS (High Accuracy Radial Velocity Planet Searcher), which has been responsible for discovering hundreds of exoplanets over the last 17 years," said study co-author Francesco Pepe from the University of Geneva. "We're really