Civilizations From Oldest Stars Had Enough Time To Reach Earth If They Wanted To: Researchers. Washington: If alien life really exists, they would have found humans by now, but consciously avoiding us for unknown reasons, a new study has suggested. Researchers, who calculated the time a society would take to muster up resources and know-how to travel to another world, found that alien civilizations starting from the oldest stars in the galaxy would have had more than enough time to reach Earth.