TRAPPIST-1: Good News and Bad News

TRAPPIST-1 opens up an exciting field for astronomers: a small, nearby, compact planetary system with seven Mars- to Earth-size worlds orbiting in days or weeks instead of months and years. What’s more, because their star is small and cool, all the planets may be habitable. Maybe. Two new papers are out on TRAPPIST-1. One makes the chances for life even more ripe, while the other virtually strips away all chances of habitability. The Bad News Let’s step back: until the last decade or so