Question

When did the Big Bang occur ?

Answer 1

According to scientists, the Big Bang occurred 13.8 billion years ago

Hope this helps

Answer 2

13.8 billion years ago

This relic radiation is known as the cosmic microwave background radiation. The chemistry of life may have begun shortly after the Big Bang, 13.8 billion years ago, during a habitable epoch when the universe was only 10–17 million years old.