 While conducting a program of observations designed to uncover near @-@ Earth objects , the Shoemakers and Levy discovered Comet Shoemaker – Levy 9 on the night of March 24 , 1993 in a photograph taken with the 0 @.@ 4 m ( 1 @.@ 3 ft ) Schmidt telescope at the Palomar Observatory in California . The comet was thus a serendipitous discovery , but one that quickly overshadowed the results from their main observing program . 
