The Earth-size worlds orbit a star just 39 light-years away, and most may have the right conditions to host liquid water on their surfaces.
ILLUSTRATION BY M. KORNMESSER, SPACEENGINE.ORG/ESO |
Seven rocky planets orbiting a nearby star may be roughly the size of Earth and could even be right for water—and maybe life—to adorn their surfaces, researchers announced Wednesday.
The planets, which circle a star called TRAPPIST-1 just 39 light-years away, are tucked together so tightly that they routinely spangle each others’ skies, sometimes appearing as shimmering crescents and at other times as orbs nearly twice as large as the full moon.
“The spectacle would be beautiful,” says the University of Cambridge’s Amaury Triaud, coauthor of a study describing the otherworldly heptad that appears in the journal Nature.
The TRAPPIST-1 system is now tied with several others that have seven planets for the greatest number of planets in a stellar system other than our own (which has eight, not counting dwarf planets like Pluto). The system’s existence suggests that Earth-size planets are much more plentiful than previously imagined.
And now, it’s among the best neighborhoods to study for signs of life beyond Earth: The relative sizes of the planets and star, plus the system’s proximity, mean that plucking the signatures of living, breathing organisms from the planet’s atmospheres could be within reach.