What Are Alien Species Like? Symmetrical, Solid, and Seeing (Probably)

Welcome to another juicy installment of the Codex Futurius project, this blog’s never-ending quest to explore the timeless scientific ideas raised by science fiction. This question about what kind of aliens we may eventually run into goes to Rocco Mancinelli of SETI. Thanks to Dr. Mancinelli for the enlightening contribution and to Jennifer Ouellette, the director the NAS’ Science and Entertainment Exchange (SEEx) program, for connecting us with him. What is the most likely form an alien would take? Life’s architecture is difficult to predict because it depends on many factors involving the interaction of the environment and life through evolution and natural selection. We can, however, make some generalizations based on the vast number of morphological forms that life takes on earth. Life on earth ranges from microscopic spheres and rods to macroscopic creatures exhibiting wide variations in their morphologies (e.g., spiders to humans). Nevertheless, nearly all life (everything ...