> Because the planets are so close to Trappist-1, they have quite likely become “gravitationally locked” to the star, always with one side of the planets facing

> Because the planets are so close to Trappist-1, they have quite likely become “gravitationally locked” to the star, always with one side of the planets facing the star, much as it is always the same side of Earth’s moon facing Earth. Also, during the live stream they said that the furthest planet does a complete orbit around the star in 20 Earth days. So there are likely no 'days' on any of these planets and a 'year' goes by in less than a month on Earth.