The TRAPPIST-1 system is a science-fiction writer's dream. Seven Earth-sized worlds orbit a red dwarf star just 40 light-years away. Three of those worlds are within the habitable zone of the star.

If you were to hop on a ship traveling at the speed of light and head out into the galaxy for 40 years, you might come across a cool, red star circled by seven worlds. Some of those seven Earth ...

This 2018 artist's concept shows what the TRAPPIST-1 planetary system may look like, based on available data about the planets' diameters, masses and distances from the host star (far left).

If you are going to look for intelligent life beyond Earth, there are few better candidates than the TRAPPIST-1 star system. It isn't a perfect choice. Red dwarf stars like TRAPPIST-1 are ...

A small, cool star in distant space plays host to something amazing. Scientists have discovered that at least seven Earth-sized worlds circle the star TRAPPIST-1, a ultracool dwarf star only about ...