Ana watsa saƙon a cikin sararin samaniya sau ɗaya ta hanyar raƙuman rediyo da aka daidaita ta hanyar sauyawa a cikin sararin samaniya a wani bikin don yin alama da sake fasalin telescope na rediyo na Arecibo a Puerto Rico a ranar 16 ga Nuwamba 1974. An aika da saƙon zuwa wurin M13 na yanzu kimanin shekaru 25,000 na haske saboda M13 babban abu ne da kuma kusa da tarin taurari wanda yake samuwa a sama a lokacin da wurin bikin. Sakon ya ƙunshi lambobi 1,679 na binary, kimanin 210 bytes, wanda aka watsa a mita 2,380 MHz kuma an daidaita shi ta hanyar sauyawa ta hanyar 10 Hz, tare da ikon 450 kW.
Shekara ta 1974