Two of Jupiter's satellites, Europa and Ganymede, pull Io into an elliptical orbit around Jupiter. Differences in the strength of Jupiter's gravitational pull as the distance between the planet and Io varies causes slight changes in Io's shape. Scientists believe that Io heats up internally when it changes shape.
The Atomic Age, also known as the Atomic Era, is the period of history following the detonation of the first nuclear (atomic) bomb, Trinity, on July 16, 1945 during World War II.
Atomic energy. Atomic energy is energy carried by atoms. The term originated in 1903 when Ernest Rutherford began to speak of the possibility of atomic energy. The term was popularized by H. G. Wells in the phrase, splitting the atom, devised at a time prior to the discovery of the nucleus. Atomic energy may include: