History of Atmospheric Research
Scientific studies of Earth's atmosphere began in the mid-17th century, when scientists discovered that the atmosphere exerts pressure on the surface of Earth. These early studies were limited mainly to temperature and pressure measurements taken from various altitudes on Earth's surface and from instrument-carrying kites. During the late 18th and early 19th centuries, manned, instrument-carrying balloons were used to measure temperature, pressure, humidity, magnetic-field strength, and other properties of the atmosphere up to altitudes of about 25,000 feet (7,600 m). Unmanned balloons have been used since the close of the 19th century, when automatically recording instruments became available.
In the 1920s, radio signals were used to determine the location and extent of the ionosphere. Since the late 1940s, rocket-borne instruments have been used to investigate the upper atmosphere. They provide data on such things as atmospheric composition, solar radiation, cosmic rays, ion and particle densities, and auroras. Detailed studies of the ionosphere and magnetosphere began with the development in the 1960s of scientific satellites that were launched into Earth orbit. Instruments on space probes have provided scientists with detailed data on the atmosphere of Venus, Mars, and other planets.