The Chicago Astronomical Society (CAS) is a non-profit organization dedicated to promoting the study and enjoyment of astronomy. Founded in 1862, it is one of the oldest astronomical societies in the United States. CAS offers educational programs, public observing events, and access to telescopes for both members and the general public. The society hosts regular meetings, lectures, and workshops to engage enthusiasts of all ages. Members can participate in various activities, including star parties and outreach programs, aimed at fostering a love for astronomy and increasing awareness of celestial phenomena.