Thunderstorms. Space shuttle image of multiple thunderstorm cells (lower frame and at upper right) in Earth's atmosphere. This view is from the space shuttle Discovery, at a distance of around 240 kilometres. These thunderstorms are located about 16 degrees south-east of Hawaii in the Pacific Ocean. Examples of every stage of a developing thunderstorm are present, from the building cauliflower tops to the mature anvil phase. The flattened anvil tops of the clouds form at an altitude of around 15 kilometres, at the tropopause, the boundary between the troposphere and stratosphere. Photographed on mission STS-64 (9-20 September 1994).