Astronomers have recently announced that there is a brand new Earth-like planet that's been discovered orbiting a nearby star – and this one holds the best chance for life.
The planet, known as Ross 128b, is located a mere 11 light-years from Earth, and will one day become the closest exoplanet to our Sun, dethroning our current immediate neighbour exoplanet – Proxima Centauri b.
The Ross 128b planet 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 abroad 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.
"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."
Ross 128b is a far more relaxed star than the likes of TRAPPIST–1 or other nearby stellar friends. Scientists believe this because it creates conditions more favourable for life. It is hard to survive when your parent star is constantly slinging radioactive flares or is rapidly heating or cooling. HARPS spotted evidence for the existence of the newly discovered exoplanet around the red draw star Ross 128. Based on the data, the team estimated that the imaginatively-named exoplanet Ross 128b orbits its star at the equivalent of one twentieth the distance between the Earth and Sun.
It is expected to have a surface temperature close to that on our own planet. Ross 128b only absorbs about 1.38 times as much radiation as our planet, giving the Earth-sized world a hospitable equilibrium temperature in the range of -60 to 20 ºC. This is because the red dwarf is much smaller and cooler than our star.
Ross 128b has many of the hallmarks that make for a promising target in the search for extraterrestrial life as it shares many similarities to Earth, the only world on which life is known to exist.
There is, however, a major question mark over the habitability of the exoplanet. The team behind the discovery of the exoplanet is not certain if it orbits within the habitable zone of its star – the region of space in which a planet receives the correct amount of radiation to allow liquid water to exist on its surface.
It has definitely been a fantastic year for discovering new planets in our solar system.