Three new super-Earths that could support life, relatively nearby
An artist’s impression of the view from the surface of exoplanet Gliese 667Cd, looking towards the planet’s parent star, Gliese 667C. A record-breaking three planets in this system are possible candidates for the presence of life. (Image credit: ESO/M. Kornmesser)
A team of astronomers has announced that a star in the (relatively) nearby Scorpion constellation hosts a system of six planets -- three of which are super-Earths sitting in the habitable zone where liquid water, and therefore life, could exist.
The discovery sets a new record: astronomers have never before found three planets like this all in the habitable zone of the same system. Super-Earths are planets with more mass than our Earth but less than a planet like Uranus or Neptune.
According to the announcement, this star, Gliese 667c, is very well studied -- three planets had already been discovered orbiting it, one of which sits in the habitable zone.
But the new discovery occurred after a team led by researchers in Germany and the U.K. re-examined the star using data from the European Southern Observatory's Very Large Telescope in Chile; the Magellan II telescope, also in Chile; the Keck telescope in Mauna Kea, Hawaii; and other pre-existing research.
"Instead of looking at ten stars to look for a single potentially habitable planet, we now know we can look at just one star and find several of them,” said co-author Rory Barnes of the University of Washington in a statement. In theory, that means there could be a higher number of habitable planets in the solar system.
Gliese 667c is a third of the mass of our sun and sits 22 light years away in a triple star system -- so anyone sitting on one of the newly-discovered planets and looking up would see a regular sun and two very bright stars that, at night, would provide as much light as a full moon, according to the announcement.
The discovery of the new planets means the system is so chock-full it could not support the orbit of another planet.
The research will appear in the journal Astronomy and Astrophysics.
Kate Allen is the Star's science and technology reporter. Find her on Twitter at @katecallen.