TRAPPIST-1 has a solar system like no other. The tiny, tiny red dwarf is just barely big enough to be considered a star, and is, radius-wise, a hair bigger than Jupiter. When it was announced last May, there was some excitement: the system had three Earth-sized planets, and they might all be habitable.
We’re going to have to revise that, though. It has seven planets. The results of an intensive study were published today in Nature.
TRAPPIST-1 is so small that it resembles Jupiter and