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.
Geological Dating Next, let's move on to something really simple and straightforward-the geological dating of the earth. According to the experts at the Scopes Trial, radium emanations showed that: The earth was at least 100 million years old. The Palaeozoic Era began at least 50 million years ago. The Mesozoic Era began at least 25 million years ago. And our present time period, the Cenozoic Era began 5-10 million years ago.