The Earth-sized planets are orbiting their parent star, located in the constellation Aquarius relatively close to Earth at 40 light years away, at a distance that provides the right amount of heat for there to be liquid water on their surface, a condition scientists believe may be critical for fostering life.
The discovery marked the first time that planets were found orbiting a common type of star known as an ultra-cool dwarf, the scientists said.
“If we want to find life elsewhere in the universe, this is where we should start to look,” Michael Gillon, lead author of the research published in the journal, said.
The discovery was made using Europe’s Transiting Planets and Planetesimals Small Telescope, or TRAPPIST, located in Chile.
Though the planets are about the size of Earth, their host star is just 8% of the size of the sun and less than a half a percent as bright.
So far, astronomers have found more than 2,000 planets beyond the solar system and are developing techniques to scan planets’ atmospheres for gases related to biological activities.