(6-18-19) Alien life exists in all shapes and sizes somewhere out there in space, according to the Fermi Paradox. Proposed in the 1970’s and named after the physicist Enrico Fermi, the paradox estimates the probability that intelligent alien civilizations exist, even if we have never seen proof.

(6-17-19) Seth Shostak is the senior astronomer at the SETI Institute (Search for Extraterrestrial Intelligence) in Mountain View, California. His job is to listen for signals from intelligent extraterrestrial sources in space.