The NASA Spitzer Space Telescope has discovered a system of seven Earth-sized planets 40 light-years away. Some of these planets may harbor oceans of water on their surfaces, which means they “could play host to life,” according to astronomers.
“This is an amazing planetary system—not only because we have found so many planets, but because they are all surprisingly similar in size to the Earth,” said Michaël Gillon of the STAR Institute at the University of Liège in Belgium, who authored a research paper on the news entitled “Seven temperate terrestrial planets around the nearby ultracool dwarf star TRAPPIST-1,” which will be published in the journal Nature.
The team determined that all the planets in the system are similar in size to Earth and Venus in the Solar System, or slightly smaller. The planetary orbits are not much larger than that of Jupiter’s Galilean moon system, and much smaller than the orbit of Mercury in the Solar System. All seven planets discovered in the system could potentially have liquid water on their surfaces, though their orbital distances make some of them more likely candidates than others.