Washington: Astronomers have found at least seven Earth-sized planets orbiting the same star 40 light-years away, according to a study published Wednesday in the journal Nature. The findings were also announced at a news conference at NASA Headquarters in Washington.
This discovery outside of our solar system is rare because the planets have the winning combination of being similar in size to Earth and being all temperate, meaning they could have water on their surfaces and potentially support life.
"This is the first time that so many planets of this kind are found around the same star," said Michaël Gillon, lead study author and astronomer at the University of Liège in Belgium.
The seven exoplanets were all found in tight formation around an ultracool dwarf star called TRAPPIST-1.
Estimates of their mass also indicate that they are rocky planets, rather than being gaseous like Jupiter. Three planets are in the habitable zone of the star, known as TRAPPIST-1e, f and g, and may even have oceans on the surface.
The researchers believe that TRAPPIST-1f in particular is the best candidate for supporting life. It's a bit cooler than Earth, but could be suitable with the right atmosphere and enough greenhouse gases.
If TRAPPIST-1 sounds familiar, that's because these researchers announced the discovery of three initial planets orbiting the same star in May. The new research increased that number to seven planets total.
"This discovery could be a significant piece in the puzzle of finding habitable environments, places that are conducive to life," said Thomas Zurbuchen, associate administrator of NASA's Science Mission Directorate.