New Earths discovered in Galaxy: Super- Earths Could Host Life
Scientists have discovered new earths they call super-earths, in the galaxy that could support life.
The newly discovered planets are orbiting around a nearby star Gliese 667C that is merely 22 light-years from our earth. They are orbiting “habitable zone” of the star which means that the temperature in these planets is such that liquid water could occur. Scientists cautioned that it is impossible to ascertain at this time what the conditions are like on these planets. Researchers called these exoplanets super-earths because they are bigger than the earth but less massive that Neptune. Scientists believe that their orbit makes them likely candidates for hosting life.
According to researchers, Gliese 667C is overflowing with planets. There are possibly seven planets that orbit Gliese 667C. Scientists said that the star belongs to a triad system which means that three suns are visible from these planets in their daytime skies. According to researchers, the planets orbiting the habitable zone and those closer to Gliese 667C are expected to always have the same side facing the star, so that their day and year will be of equal lengths, with one side in perpetual sunshine and the other always dark.
“The other stars in the triple system would provide a unique sunset: the two other suns would look like a pair of very bright stars visible in the daytime and at night they would provide as much illumination as the full Moon,” scientists said.
This planetary system is in the constellation of Scorpius .
Initially, scientists in their previous studies had recognized only three likely planets orbiting around the star Gliese 667C, with one only one super-earth dwelling its habitable zone. The scientist called this planet super-earth because it is bigger than our earth. But with new research, scientists have revealed a complement of planets around Gliese 667C. The study was carried out by an international team of scientists.
“We knew that the star had three planets from previous studies, so we wanted to see whether there were any more,” co-leader of the study Mikko Tuomi of the University of Hertfordshire, U.K. said in a statement. “By adding some new observations and revisiting existing data we were able to confirm these three and confidently reveal several more. Finding three low-mass planets in the star’s habitable zone is very exciting!”
The host of telescopes used by researchers included the powerful telescope at the Silla Observatory in Chile. This telescope incorporates the High Accuracy Radial Velocity Planet Searcher (HARPS) dedicated to the discovery of extrasolar planets.
Scientists explain, “Harps employs an indirect method of detection that infers the existence of orbiting planets from the way their gravity makes a parent star appear to twitch in its motion across the sky.”
Exoplanets, also referred to as extrasolar planets, are objects outside of the solar system. Beginning in 1992 with the initial discovery, astronomers have found approximately 837 such planets in 660 planetary systems around the Milky Way galaxy. Researchers think they will find many more planets. A study done in 2012 estimated that each star of the 100 billion or so in the Milky Way galaxy hosts on average at least 1.6 planets.
According to scientists, if all seven planets are established, the system would consist of three habitable-zone super-Earths, two hot planets further in, and two cooler planets further out.
By Perviz Walji
Sources: BBC News, NASA, HuffPost Science, Universe Today