It seems that a SETI (Search for Extra Terrestrial Intelligence) experiment happened decades before the Project Ozma occurred in 1960. The historians at the blog Letters of Note have uncovered a telegram sent in 1924 by then Chief of Naval Operations Edward W. Eberle instructing the United States Navy to listen for radio transmissions from the planet Mars.
The telegram read:
“NAVY DESIRES COOPERATE ASTRONOMERS WHO BELIEVE POSSIBLE THAT MARS MAY ATTEMPT COMMUNICATION BY RADIO WAVES WITH THIS PLANET WHILE THEY ARE NEAR TOGETHER THIS END ALL SHORE RADIO STATIONS WILL ESPECIALLY NOTE AND REPORT ANY ELECTRICAL PHENOMENON UNUSUAL CHARACTER AND WILL COVER AS WIDE BAND FREQUENCIES AS POSSIBLE FROM 2400 AUGUST TWENTY FIRST TO 2400 AUGUST TWENTY FOURTH WITHOUT INTERFERRING WITH TRAFFIC”
During the three day period, during which Mars was in opposition to Earth, nothing but static was detected by Navy radio stations.
Of course it is too bad that this odd bit of history did not become known when the X Files was still in production, as it would have made for an interesting story line.