An international team of astronomers has discovered a temperate Earth-sized world with the potential to harbor alien life. The planet, known as Ross 128 b, is located a mere 11 light-years from Earth, and will one day become the closest exoplanet to our Sun, dethroning our current immediate neighbor exoplanet – Proxima b.
Ross 128 b was discovered by researchers using the European Southern Observatory’s (ESO) High Accuracy Radial Velocity Planet Searcher (HARPS) located at the La Silla Observatory in Chile. The HARPS instrument, which is mounted aboard a 3.6-meter optical and near-infrared telescope, does not directly observe exoplanets, but instead watches for a minute wobble in the motion of a host star created by the gravitational influence of an orbiting world.
Astronomers are able to use HARPS data to estimate certain characteristics of an exoplanet, such as its mass, orbital period, and distance from its host star. Exoplanets discovered by HARPS can then be examined in further detail by other instruments and observatories, including the ESO’s Extremely Large Telescope, which is expected to achieve first light in 2024.
“This discovery is based on more than a decade of HARPS intensive monitoring together with state-of-the-art data reduction and analysis techniques,” comments Nicola Astudillo-Defru of the University of Geneva, Switzerland, who co-authored the discovery paper. “Only HARPS has demonstrated such a precision and it remains the best planet hunter of its kind, 15 years after it began operations.”