In popular cultures, "Extraterrestrials" are life forms — especially intelligent life forms— that are of extraterrestrial origin (often also called "aliens").
Famous quotes containing the word life:
“We’ve only just begun to learn about the water and its secrets, just as we’ve only touched on outer space. We don’t entirely rule out the possibility that there might be some form of life on another planet. Then why not some entirely different form of life in a world we already know is inhabited by millions of living creatures?”
—Harry Essex (b. 1910)