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.
For religious and other non-scientific estimates, see Dating creation. In physical cosmology, the age of the universe is the time elapsed since the Big Bang. The current measurement of the age of the universe is 7001137990000000000â 13.799Â±0.021 billion (109) years within the Lambda-CDM concordance model.