Astronomers have found an Earth-sized planet with mild temperatures that's also relatively close to our Solar System.
It was discovered by a team of researchers who are using the European Space Agency's High Accuracy Radial velocity Planet Searcher (HARPS) at the La Silla Observatory in Chile. Now we welcome a new tantalizing exoplanet to the group, the second closest we know of, also Earth-sized and temperate, orbiting a calm red dwarf star: Ross 128 b.
A red dwarf is a particularly faint & cool star, and astronomers say it is easier to detect Earth-like planets orbiting around them than it is detecting ones that orbit around stars similar to our Sun.
"HARPS is a spectrograph specially created to measure the radial velocity of the stars", Nicola Astudillo-Defru, an astronomer with the Geneva Observatory in Switzerland and a member of the team that made the discovery, told Popular Mechanics in an e-mail. Around this period, Ross 128 b will then take over from Proxima b and become the closest exoplanet to Earth!
The astronomers believe that Ross 128 b is a good candidate for further study when the European Southern Observatory's Extremely Large Telescope can begin searching the atmospheres of exoplanets for biomarkers in 2025.
Ross 128 is an old, inactive red dwarf star that sits 11 light-years away.
This image shows the sky around the red dwarf star Ross 128 in the constellation of Virgo (The Virgin).
Co-discoverer Nicola Astudillo-Defru from the Geneva Observatory in Switzerland said the find was the result of more than a decade of intensive monitoring using the Harps instrument.
A newfound exoplanet may be one of the best bets to host alien life ever discovered - and it's right in Earth's backyard, cosmically speaking.
In the search for habitable worlds beyond our Solar System, astronomers generally look for low-mass, rocky and temperate planets much like our own.
You may want to get used to the name Ross 128 b. But Proxima b's parent star, Proxima Centauri, blasts out a lot of powerful flares, potentially bathing that planet in enough radiation to stunt the emergence and evolution of life, scientists have said. Follow-up observations are needed to determine whether Ross 128 b orbits within or near the habitable zone where liquid water could exist on the planet's surface. Ross 128 b could change this, because the planet and its star are moving toward us. Even so, due to a variety of factors Ross 128 b is tied for fourth on a list of potentially most habitable exoplanets, with an Earth Similarity Index value of 0.86.
But Ross 128 doesn't seem to be doing this, so it's considered "quieter", which means the planet is a more comfortable place for life to form without being subjected to such violent episodes from time to time.
It might now be 11 light-years from Earth, but Ross 128 is moving towards us and is expected to become our nearest stellar neighbour in 79,000 years.