Elon Musk has turned a long-running joke about being an extraterrestrial into a central part of his public persona, even as he argues that humanity may be the only intelligent life in the universe.

If humanity ever makes contact with an intelligent extraterrestrial civilization, we will have no shortage of questions.

Add Yahoo as a preferred source to see more of our stories on Google. (Photo by BRENDAN SMIALOWSKI/AFP via Getty Images) A new genetic study claims alien DNA could be inserted into humans. Dr. Max ...