In the silence behind the moon, where Earth's ceaseless radio noise cannot follow, humanity is preparing to listen for the oldest sound the cosmos has ever made. CosmoCube, a compact satellite developed by researchers at the Royal Astronomical Society and the University of Cambridge, will orbit the lunar far side before this decade ends, using the moon as a natural shield to capture the 21-centimeter signal of neutral hydrogen — a whisper from the universe's infancy, before the first stars had yet ignited. The mission reaches toward the Cosmic Dark Ages, a chapter of cosmic history that has re