According to the most accepted theory about the origin of the universe, it would have expanded from a huge explosion (in English, big bang). Astronomers raised this argument from the observation that galaxies are moving away from each other, as if the cosmos continue exploring. The groups of the distant stars are the fastest split. This view was originally described by the American astronomer Edwin Hubble. The theory holds that as the celestial bodies were moving away from each other, they cooled, which allowed from the masses of incandescent gas to form solid masses, including planets.
Some astronomers questioned the Big Bang theory and maintain that over a period of 20 000 million years ago could not have been recently discovered massive galaxies form.
The big bang theory permitted the inference that age of the universe would be between 15,000 and 20,000 million years.