Adamski was born on April 17, 1891 in Poland. At the age of 2, he and his family immigrated to America and settled in New York City. At the age of 22, from 1913 to 1916, he was a soldier in the 13th U.S. Cavalry Regiment K-Troop fighting at the Mexican border during the Pancho Villa Expedition. In 1917, he married. Adamski then moved west, working as a maintenance worker in Yellowstone National Park, and as a worker in an Oregon flour mill. While in Laguna Beach, Adamski founded the "Royal Order of Tibet," which held its meetings in the "Temple of Scientific Philosophy." In 1940, Adamski and some close friends of his moved to a ranch near California's Palomar Mountain where they dedicated their time to studying and farming. In 1944, with funding from Mrs. Alice K. Wells, a student of Adamski, they purchased of land on Palomar Mountain, where they built a new home called Palomar Garden and a new restaurant called Palomar Gardens Cafe.

On October 9, 1946, during a meteor shower, Adamski and some friends claimed that while they were at the Palomar Gardens' campground, they witnessed a large cigar-shaped "mother ship". In 1947, Adamski took a photograph of what he claimed was the 1946 cigar-shaped "mother ship" crossing in front of the moon over Palomar Gardens.