SOLAR SYSTEM

Detailed explanation-1: -On October 4, 1957, the Soviet Union launched the earth’s first artificial satellite, Sputnik I .

Detailed explanation-2: -Sputnik 1 (/ˈspʌtnɪk, ˈspʊtnɪk/; see § Etymology) was the first artificial Earth satellite.

Detailed explanation-3: -Sputnik, any of a series of three artificial Earth satellites, the first of whose launch by the Soviet Union on October 4, 1957, inaugurated the space age. Sputnik 1, the first artificial satellite launched, was a 83.6-kg (184-pound) capsule.

Detailed explanation-4: -Officially, Sputnik was launched to correspond with the International Geophysical Year, a solar period that the International Council of Scientific Unions declared would be ideal for the launching of artificial satellites to study Earth and the solar system.

Detailed explanation-5: -Aryabhata was the first artificial satellite launched by India on 19th April 1975.