AN UNUSUAL NEW SOLAR SYSTEM has everyone's attention. Astronomers discovered seven Earth-size worlds orbiting a cool, red star named TRAPPIST-1 (after the small Chilean telescope that found the first three worlds) a mere 39 light-years away. The planets are all orbiting very close to the star, and in the right orientation, so astronomers are able to see lots of transits in a short amount of time. With NASA's Spitzer telescope, astronomers were able to see that one of those first three planets was actually four. Earth-size doesn't necessarily mean Earth-like, but with several of the worlds in the habitable zone, the TRAPPIST-1 system will be closely inspected for a long time.
展开▼
