Partially driven by the science fiction following Lowell’s drawings, the early 20th century saw increased interest in detecting radio signals from Outer Space. This interest accelerated after the launch of Sputnik in 1957 and was more systematically and formally approached starting in the late 1970s. SETI research has not been publicly funded since 1994, but private and public donors, as well as academic and lay researchers have kept the program going since. There are many technical challenges to the search: space is unimaginably huge, signals are weak, possibilities of interstellar communication are myriad, and our searches can only cover an insignificant portion of the task.