Three earth-like planets have been discovered by astronomers probing the outer reaches of space, according to an article in the latest issue of Nature. These planets offer possibilities of finding life outside our solar system, the magazine said.
“This is the first opportunity to find chemical traces of life outside our solar system,” said lead author Michael Gillon, an astrophysicist at the University of Liege in Belgium. All three planets had the “winning combination” of being similar in size to Earth, “potentially habitable” and close enough so their atmospheres can be analysed with current technology, he told mediapersons.
The three planets orbit a terribly cold dwarf star some 39 light years away, and seem to be comparable in size and temperature to Earth and Venus.
“Star-like objects with effective temperatures of less than 2,700 kelvin are referred to as ‘ultracool dwarfs’. This heterogeneous group includes stars of extremely low mass as well as brown dwarfs…there could be planets ranging from metal-rich Mercury-sized planets to more hospitable volatile-rich Earth-sized planets.”
The scientists said in Nature: “Here we report observations of three short-period Earth-sized planets transiting an ultracool dwarf star only 12 parsecs away. The inner two planets receive four times and two times the irradiation of Earth, respectively, placing them close to the inner edge of the habitable zone of the star8. Our data suggest that 11 orbits remain possible for the third planet…The infrared brightness of the host star, combined with its Jupiter-like size, offers the possibility of thoroughly characterizing the components of this nearby planetary system.”
The planets are referred to as “red worlds” due to the dark red colour reflected off of the TRAPPIST-1, a star barely larger than Jupiter. As an ultra-cool dwarf star, it has a temperature of less than 2,700 kelvin – more than 2,000 C – making it half as hot as the sun, according to a report by CTV News.
Australian media reported that the find opened up possibilities for new, habitable planets and the Belgian scientists had calibrated a 60-centimetre telescope in Chile, known as TRAPPIST, to track several dozen dwarf stars neither big nor hot enough to be visible with optical telescopes. They zeroed in on a particularly promising one, now known as TRAPPIST-1, about one eighth the size of the Sun, and significantly cooler. It was here that they found the planets. – CINEWS