Using the 60-centimeter (24-inch) telescope TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope) in Chile, astronomers have discovered three Earth-like exoplanets orbiting a dwarf star in the galaxy TRAPPIST-1.
What makes the find significant is that there is a possibility that these three planets can support life. The exoplanets may represent mankind's best-ever chance of finding signs of alien life outside the solar system.
"Systems around these tiny stars are the only places where we can detect life on an Earth-sized exoplanet with our current technology," said Michaël Gillon, from the University of Liège in Belgium. "So if we want to find life elsewhere in the universe, this is where we should start to look."
The proximity of the two planets TRAPPIST-1b and 1c to the dwarf star suggests that they get about four times the amount of radiation that the Earth receives from the sun.
The two extraterrestrial bodies are also in the inner edge of the "habitable zone," the region around a star where the temperature of the planet can support liquid water at the surface. Mankind's quest for extraterrestrial life currently involves looking for signs of liquid water such as in the case of life-hunting missions on planet Mars.
"What is super exciting is that for the first time, we have extrasolar worlds similar in size and temperature to Earth-planets that could thus, in theory, harbor liquid water and host life on at least a part of their surfaces-for which the atmospheric composition can be studied in detail with current technology," said Gillon.
The two planets are tidally locked which means that one side always faces the star. The daysides of the two exoplanets may be too hot to support life but a twilight region between day and night may make balmy temperatures and Earth-like weather possible.
Scientist, however, said that while these Earth-like worlds possess habitable regions on their surfaces, other factors such as clouds and atmosphere, can make it difficult to predict whether or not the surface conditions are really suitable for supporting life.
Little is known about the third planet, TRAPPIST-1d, but it is believed to be on the outer rim of the habitable zone and receives twice the amount of radiation we get from the sun.
The discovery was reported in a study published in the journal Nature on May 2.
