Resources can be extraterrestrial.Logical formLearned from18 sentences. A communication can be extraterrestrial.Logical formLearned from18 sentences. Artifacts can be extraterrestrial.Logical formLearned from17 sentences. Forces can be extraterrestrial.Logical formLearned from17 sentences. Extraterrestrial civilizations can be in the universe.Logical formLearned from17 sentences. A threat can be extraterrestrial.Logical formLearned from17 sentences. (Radio signals) can be extraterrestrial.Logical formLearned from17 sentences. A version can be extraterrestrial.Logical formLearned from17 sentences. An extraterrestrial being may infiltrate minds.Logical formLearned from17 sentences. Encounters can be extraterrestrial.Logical formLearned from17 sentences. An exploration can be extraterrestrial.Logical formLearned from16 sentences. Planets can be extraterrestrial.Logical formLearned from16 sentences. Invaders can be extraterrestrial.Logical formLearned from16 sentences. Signs can be constituted-of-or-filled-with extraterrestrial intelligence.Logical formLearned from16 sentences. A proof of extraterrestrial intelligence may begin as a spike.Logical formLearned from16 sentences.