Heavy Planet includes Hal Clement’s famous science fiction novel, Mission of Gravity and its lesser known sequel, Star Light. The premise of Mission of Gravity is a mission to recover a scientific probe on the super-jovan planet of Mesklin where the surface gravity varies from 3 Earth gravities at the the equator to 700 Earth gravities at the poles. On this high-gravity planet, a “day” is 18 minutes! And yet, Mesklin has life in the form of intelligent, centipede-like creatures. Mission of Gravity was published in 1953 and Star Light was published in 1973. If you haven’t read these wonderful science fiction novels, you’re in for plenty of delight! Highly recommended!