Activity Notes For related resources in Spanish, see the Explora Más en Español section below. The "Pi in the Sky" math challenge gives students a chance to take part in recent discoveries and upcoming celestial events, all while using math and pi just like NASA scientists and engineers. In this problem from the set , students use the mathematical constant pi to find the "habitable zone" around a distant star, TRAPPIST-1, and determine which of its planets are in that zone. Materials Pi in the