Editing Magnetosphere (section)

==History==
{{main|Magnetosphere chronology}}
Study of Earth's magnetosphere began in 1600, when [[William Gilbert (astronomer)|William Gilbert]] discovered that the magnetic field on the surface of Earth resembled that of a [[terrella]], a small, magnetized sphere. In the 1940s, [[Walter M. Elsasser]] proposed the model of [[dynamo theory]], which attributes [[Earth's magnetic field]] to the motion of Earth's [[iron]] [[outer core]]. Through the use of [[magnetometer]]s, scientists were able to study the variations in Earth's magnetic field as functions of both time and latitude and longitude.

Beginning in the late 1940s, rockets were used to study [[cosmic rays]]. In 1958, [[Explorer 1]], the first of the Explorer series of space missions, was launched to study the intensity of cosmic rays above the atmosphere and measure the fluctuations in this activity. This mission observed the existence of the [[Van Allen radiation belt]] (located in the inner region of Earth's magnetosphere), with the follow-up [[Explorer 3]] later that year definitively proving its existence. Also during 1958, [[Eugene Parker]] proposed the idea of the [[solar wind]], with the term 'magnetosphere' being proposed by [[Thomas Gold]] in 1959 to explain how the solar wind interacted with the Earth's magnetic field. The later mission of [[Explorer 12]] in 1961 led by the Cahill and Amazeen observation in 1963 of a sudden decrease in magnetic field strength near the noon-time meridian, later was named the [[magnetopause]]. By 1983, the [[International Cometary Explorer]] observed the [[Magnetosphere#Magnetotail|magnetotail]], or the distant magnetic field.<ref name="Van Allen"/>