Search for Alien Life Needs Human Mars Missions, NASA Chief Scientist Says

"I am someone who believes it is going to take humans on the surface [of Mars] … to really get at the question of not just did life evolve on Mars, but what is the nature of that life," Stofan said at a scientific workshop in Irvine, California, hosted by the National Academy of Sciences. The workshop, titled "Searching for Life Across Space and Time," drew together leading scientists who are, through various avenues, working to find signs of alien life in Earth's solar system and beyond.