2102 Tantalus was discovered by C. Kowal at the Palomar Observatory (an astronomical observatory in San Diego County, California) on 27 December 1975.
27 December 1975 Palomar Observatory is an astronomical observatory in San Diego County, California, United States, 145 kilometers (90 mi) southeast of Los Angeles, California, in the Palomar Mountain Range. Tantalus C. Kowal Palomar Observatory 
