Horsham holds the UK record for the heaviest hailstone ever to fall. The county also holds the state's records for both maximum 24-hour snowfall and largest hailstone. Vivian holds the world record for largest measured hailstone. This determines the varying thicknesses of the layers of the hailstone. Sun Valley becomes "Stone Valley" and is run by "Conrad Hailstone" (Conrad Hilton). Here, she was slightly damaged by U.S. carrier planes which attacked Truk during Operation Hailstone. Four days later, the carriers launched their planes as part of Operation Hailstone. A similar loop appears in computations of the hailstone sequence. A cross-section through a large hailstone shows an onion-like structure. The term is from the Greek () meaning "small hailstone". The hailstone gains an ice layer and grows increasingly larger with each ascent.