Our universe is 13.8 billion years old, with life on Earth only beginning around four billion years ago. The first life could have started about one to two billion years after that start of the universe, leaving a huge time period prior to signs of life on Earth where civilisations could have developed or wiped out. Could we, therefore, have missed a civilisation in the past or is there a civilisation yet to come that we could communicate with? Many feel we should be asking, why have we not come across intelligent alien yet?