Are we alone? Or could life on alien worlds really exist? David A. Aguilar, space artist extraordinaire, shows readers what creatures living on extrasolar planets might be like, in his National Geographic children’s book “Alien Worlds: Your Guide to Extraterrestrial Life.” Here he describes the process of applying real-world astronomy, biology, and chemistry to imagine what life we might find on distant planets.


The CfA is a collaboration of Harvard College Observatory (HCO) and Smithsonian Astrophysical Observatory (SAO) and home to Harvard’s Department of Astronomy.